Merge commit 'upstream/2.0.0'

1 files changed, 80 insertions, 1018 deletions

diff --git a/RELEASE.txt b/RELEASE.txt
index dc81584..d8fdd9f 100644
--- a/RELEASE.txt
+++ b/RELEASE.txt
@@ -1,1049 +1,111 @@
-# Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 The SCons Foundation
-# src/RELEASE.txt 4720 2010/03/24 03:14:11 jars
+  A new SCons checkpoint release, 2.0.0.final.0, is now available
+  on the SCons download page:
 
+          http://www.scons.org/download.php
 
-                 SCons - a software construction tool
+  The primary purpose of this release is to remove support for Python
+  versions prior to 2.4 and streamline the SCons code base using more
+  modern python idioms.
 
-                            Release Notes
+  IMPORTANT:  In 1.3.0 and 2.0.0, explicit dependencies (configured via
+  the Depends() call) are ignored for any nodes that do not have builders.
+  This known issue[1] will typically only happen if you explicitly
+  configure a builder call to create multiple output files, some of which
+  are "hidden" from SCons by not being listed in the targets list, and then
+  use Depends() to establish an explicit dependency on a "hidden" file.
 
+  [1] See http://scons.tigris.org/issues/show_bug.cgi?id=2647 for details.
 
-This is SCons, a tool for building software (and other files).  SCons is
-implemented in Python, and its "configuration files" are actually Python
-scripts, allowing you to use the full power of a real scripting language
-to solve build problems.  You do not, however, need to know Python to
-use SCons effectively.
+  A SCons "checkpoint release" is intended to provide early access to
+  new features so they can be tested in the field before being released
+  for adoption by other software distributions.
 
-So that everyone using SCons can help each other learn how to use it
-more effectively, please sign up for the scons-users mailing list using
-the instructions on the following page:
+  Note that a checkpoint release is developed using the same test-driven
+  development methodology as all SCons releases.  Existing SCons
+  functionality should all work as it does in previous releases (except
+  for any changes identified in the release notes) and early adopters
+  should be able to use a checkpoint release safely for production work
+  with existing SConscript files.  If not, it represents not only a bug
+  in SCons but also a hole in the regression test suite, and we want to
+  hear about it.
 
-     http://scons.org/lists.php
+  New features may be more lightly tested than in past releases,
+  especially as concerns their interaction with all of the other
+  functionality in SCons.  We are especially interested in hearing bug
+  reports about new functionality.
 
+  We do not recommend that downstream distributions (Debian, Fedora,
+  etc.) package a checkpoint release, mainly to avoid confusing the
+  "public" release numbering with the long checkpoint release names.
 
+  Here is a summary of the changes since 1.3:
 
-RELEASE 1.3.0 - Tue, 23 Mar 2010 21:44:19 -0400
+  NEW FUNCTIONALITY
 
-  Please consult the CHANGES.txt file for a list of specific changes
-  since last release.
+  - There should be no new functionality or bug fixes in this checkpoint.
+    Bug fixes will be found in the 1.3.1 series of checkpoints.
 
-  Please note the following important changes in this release:
+  DEPRECATED FUNCTIONALITY
 
-    --  DEPRECATED FEATURES WILL GENERATE MANDATORY WARNINGS IN 1.3.0
+  - All features or usages deprecated in 1.3 should have been removed.
+    Uses of formerly-deprecated features should get an error.
 
-        In keeping with our deprecation cycle, the following deprecated
-        features will still be supported in 1.3.0 but will generate
-        mandatory, non-disableable warnings:
+  - The BuildDir() method and the build_dir option now get warnings.
 
-            --  Support for Python versions 1.5, 1.6, 2.0, 2.1, 2.2, and 2.3.
-            --  The overrides= keyword argument to the Builder() call.
-            --  The scanner= keyword argument to the Builder() call.
-            --  The BuildDir() function and env.BuildDir() method.
-            --  The env.Copy() method.
-            --  The SourceSignatures() function and
-                env.SourceSignatures() method.
-            --  The TargetSignatures() function and
-                env.TargetSignatures() method.
-            --  The Sig module (now an unnused stub).
-            --  The --debug=dtree, --debug=stree and --debug=tree options.
-            --  The --debug=nomemoizer option.
-            --  The Options object and the related BoolOption(),
-                EnumOption(), ListOption(), PackageOption() and
-                PathOption() functions.
+  - The SourceCode() function and its associated factory functions have
+    started their deprecation cycle and can have a warning enabled.
 
-        The mandatory warnings will be issued in order to make sure
-        users of 1.3.0 notice *prior* to the release of SCons 2.0.0, that
-        these features will be removed.  In SCons 2.0.0 these features
-        will no longer work at all, and will instead generate specific
-        fatal errors when anyone tries to use them.
+  CHANGED/ENHANCED EXISTING FUNCTIONALITY
 
-  Please note the following important changes since release 1.2.0:
+  - Any Command() or env.Command() calls that use the following Action
+    factory functions will have their targets rebuilt when upgrading
+    from any pre-2.0 release:
 
-    --  Support for Latex glosseries and acronyms has been added
+        Chmod()
+        Copy()
+        Delete()
+        Mkdir()
+        Move()
+        Touch()
 
-    --  MICROSOFT VISUAL STUDIO VERSION/ARCH DETECTION HAS CHANGED
+    (The rebuild occurs because the underlying Python class that
+    implements these functions has been changed to a new-style Python
+    class, and that changes the Python byte code and therefore the
+    build signature of the functions.)
 
-        The way SCons detects Visual Studio on Windows has changed in
-        1.3.  By default, it should now use the latest installed
-        Visual Studio version on your machine, and compile for 32 or
-        64 bits according to whether your OS is 32 or 64 bits (32/64
-        bit python makes no difference).
+  FIXES
 
-	Two new variables control Visual Studio: MSVC_VERSION and
-	TARGET_ARCH.  These variables ONLY take effect when passed to
-	the Environment() constructor; setting them later has no
-	effect.  To use a non-default Visual Studio version, set
-	MSVC_VERSION to e.g. "8.0" or "7.1".  Setting it to "xxx" (or
-	any nonexistent value) will make it print out the valid
-	versions on your system.  To use a non-default architecture,
-	set TARGET_ARCH to "x86" or "x86_64" (various synonyms are
-	accepted).
+  - MSVC/MSVS/SDK support has been improved. A number of issues with
+    determining the correct version and architecture have been resolved.
 
-	In addition, MSVC_USE_SCRIPT can be used to bypass the 
-	above autodetection; setting it to the path of a Visual
-	Studio .bat file (e.g. vcvars.bat) will cause SCons to
-	run that bat file and extract the relevant variables
-	from the result (typically %INCLUDE%, %LIB%, and %PATH%).
-	Setting MSVC_USE_SCRIPT to None bypasses the Visual Studio
-	autodetection entirely; use this if you are importing
-	the shell env and running SCons in a Visual Studio cmd window.
+  IMPROVEMENTS
 
-	Note that if you use MSVS_VERSION to build Visual Studio
-	projects from your SConstructs, MSVS_VERSION must be set to
-	the same version as MSVC_VERSION.
+  - Support for Python versions prior to 2.4 has been removed.  As of
+    this writing, we believe that SCons will still work with Python 2.3,
+    but this is not guaranteed.
+  - Code paths that included special cases for older Python versions have
+    been streamlined.
+  - The code base has been converted to use more modern idioms.  Although
+    we don't have any direct measurements (yet), we believe that SCons
+    startup time should be decreased and the overall code should run faster.
 
-        Support for HOST_OS,HOST_ARCH,TARGET_OS, TARGET_ARCH has been
-        added to allow specifying different target arch than the host 
-        system. This is only supported for Visual Studio/Visual C++
-        at this time.
+  PACKAGING
 
-    --  VISUAL C/C++ PRECOMPILED HEADERS WILL BE REBUILT
+  - No changes.
 
-        Precompiled header files built with Visual C/C++ will be
-        rebuilt after upgrading from 1.2.0 to a later release.
+  DOCUMENTATION
 
-        This rebuild is normal and will occur because the command line
-        defined by the $PCHCOM construction variable has had the $CCFLAGS
-        variable added, and has been rearranged to put the "/Fo" output
-        flag towards the beginning of the line, consistent with the
-        related command lines for $CCCOM, $CXXCOM, etc.
+  - The entries for SourceCode() and its associated factory functions now
+    state that the functions are deprecated.
 
-    --  CHANGES TO SOME LINKER COMMAND LINES WILL CAUSE RELINKING
+  DEVELOPMENT
 
-        Changes to the command line definitions for the Microsoft link.exe
-        linker, the OS/2 ilink linker and the Phar Lap linkloc linker
-        will cause targets built with those tools be to be rebuilt after
-        upgrading from 1.2.0 to a later release.
+  - Code no longer has to be compatible with Python versions back to 1.5.2.
+    Although code is tested with Python 2.3 and is still believed to work,
+    the official new floor is Python 2.4.
 
-        This relink is normal and will occur because the command lines for
-        these tools have been redefined to remove unnecessary nested $(
-        and $) character strings.
-
-    --  MSVS_USE_MFC_DIRS and MSVS_IGNORE_IDE_PATHS are obsoleted and
-        have no effect.
-
-  Please note the following important changes since release 1.1.0:
-
-    --  THE $CHANGED_SOURCES, $CHANGED_TARGETS, $UNCHANGED_SOURCES
-        AND $UNCHANGED_TARGETS VARIABLES WILL BECOME RESERVED
-
-        A future release (probably 1.3.0) will make the construction
-        variable names $CHANGED_SOURCES, $CHANGED_TARGETS,
-        $UNCHANGED_SOURCES and $UNCHANGED_TARGETS into reserved
-        construction variable names controlled by SCons itself (like
-        the current $SOURCE, $TARGETS, etc.).
-
-        Setting these variable names in the current release will generate
-        a warning but still set the variables.  When they become reserved
-        variable names, they will generate a different warning message
-        and attempts to set these variables will be ignored.
-
-        SCons configurations that happen to use these variable names
-        should be changed to use different variable names, in order
-        to ensure that the configuration continues to work with future
-        versions of SCons.
-
-    --  THE Options OBJECT AND RELATED FUNCTIONS NOW GENERATE WARNINGS
-
-	Use of the Options object, and related functions BoolOption(),
-	EnumOption(), ListOption(), PackageOption() and PathOption()
-	were announced as deprecated in release 0.98.1.  Since then,
-	however, no warning messages were ever implemented for the
-        use of these deprecated functions.
-
-        By default, release 1.2.0 prints warning messages when these
-        deprecated features are used.  Warnings about all deprecated
-        features may be suppressed by using the --warn=no-deprecated
-        command-line option:
-
-            $ scons --warn=no-deprecated
-
-        Or by using the appropriate SetOption() call in any SConscript
-        file:
-
-            SetOption('warn', 'no-deprecated')
-
-        You may optionally disable just warnings about the deprecation
-        of the Options object and its related functions as follows:
-
-            SetOption('warn', 'no-deprecated-options')
-
-        The current plan is for these warnings to become mandatory
-        (non-suppressible) in release 1.3.0, and for the use of Options
-        and its related functions to generate errors in release 2.0.
-
-  Please note the following important changes since release 0.98.4:
-
-    --  scons.bat NOW RETURNS THE REAL SCONS EXIT STATUS
-
-        The scons.bat script shipped with SCons used to exit with
-        a status of 1 when it detected any failed (non-zero) exit
-        status from the underlying Python execution of SCons itself.
-        The scons.bat script now exits with the actual status
-        returned by SCons.
-
-    --  SCONS NOW WARNS WHEN TRYING TO LINK C++ AND FORTRAN OBJECT FILES
-
-        Some C++ toolchains do not understand Fortran runtimes and create
-        unpredictable executables when linking C++ and Fortran object
-        files together.  SCons now issues a warning if you try to link
-        C++ and Fortran object files into the same executable:
-
-            scons: warning: Using $CXX to link Fortran and C++ code together.
-                    This may generate a buggy executable if the '/usr/bin/gcc'
-                    compiler does not know how to deal with Fortran runtimes.
-
-        The warning may be suppressed with either the --warning=no-link
-        or --warning=no-fortran-cxx-mix command line options, or by
-        adding either of the following lines to a SConscript file:
-
-            SetOption('warn', 'no-link')
-            SetOption('warn', 'no-fortran-cxx-mix')
-
-  Please note the following important changes since release 0.98:
-
-    --  SCONS NO LONGER SETS THE GNU TOOLCHAIN -fPIC FLAG IN $SHCXXFLAGS
-
-        The GNU toolchain support in previous versions of SCons would
-        add the -fPIC flag to the $SHCXXFLAGS construction variable.
-        The -fPIC flag has been now been removed from the default
-        $SHCXXFLAGS setting.  Instead, the $SHCXXCOM construction variable
-        (the default SCons command line for compiling shared objects
-        from C++ source files) has been changed to add the $SHCCFLAGS
-        variable, which contains the -fPIC flag.
-
-        This change was made in order to make the behavior of the default
-        C++ compilation line including $SHCCFLAGS consistent with the
-        default C compilation line including $CCFLAGS.
-
-        This change should have no impact on configurations that use
-        the default $SHCXXCOM command line.  It may have an impact on
-        configurations that were using the default $SHCXXFLAGS value
-        *without* the $SHCCFLAGS variable to get the -fPIC flag into a
-        custom command line.  You can fix these by adding the $SHCCFLAGS
-        to the custom command line.
-
-        Adding $SHCCFLAGS is backwards compatible with older SCons
-        releases, although it might cause the -fPIC flag to be repeated
-        on the command line if you execute it on an older version of
-        SCons that sets -fPIC in both the $SHCCLAFGS and $SHCXXFLAGS
-        variables.  Duplicating the -fPIC flag on the g++ command line
-        will not cause any compilation problems, but the change to the
-        command line may cause SCons to rebuild object files.
-
-    --  FORTRAN NOW COMPILES .f FILES WITH gfortran BY DEFAULT
-
-        The Fortran Tool modules have had a major overhaul with the intent
-        of making them work as-is for most configurations.  In general,
-        most configurations that use default settings should not see
-        any noticeable difference.
-
-        One configuration that has changed is if you have both a gfortran
-        and g77 compiler installed.  In this case, previous versions of
-        SCons would, by default, use g77 by default to compile files with
-        a .f suffix, while SCons 0.98.1 will use the gfortran compiler
-        by default.  The old behavior may be preserved by explicitly
-        initializing construction environments with the 'g77' Tool module:
-
-            env = Environment(tools = ['g77', 'default'])
-        
-        The above code is backwards compatible to older versions of SCons.
-
-        If you notice any other changes in the behavior of default
-        Fortran support, please let us know so we can document them in
-        these release notes for other users.
-
-  Please note the following important changes since release 0.97.0d20071212:
-
-    --  SUPPORT FOR PYTHON VERSIONS BEFORE 2.2 IS NOW DEPRECATED
-
-        SCons now prints the following warning when it is run by any
-        Python 1.5, 2.0 or 2.1 release or sub-release:
-
-            scons: warning: Support for pre-2.2 Python (VERSION) is deprecated.
-                If this will cause hardship, contact dev@scons.tigris.org.
-
-        You may disable all warnings about deprecated features by adding
-        the option "--warn=no-deprecated" to the command line or to the
-        $SCONSFLAGS environment variable:
-
-            $ scons --warn=no-deprecated
-
-        Using '--warn=no-deprecated' is compatible with earlier versions
-        of SCons.
-
-        You may also, as of this version of SCons, disable all warnings
-        about deprecated features by adding the following to any
-        SConscript file:
-
-            SetOption('warn', 'no-deprecated')
-
-        You may disable only the specific warning about running under
-        a deprecated Python version by adding the following to any
-        SConscript file:
-
-            SetOption('warn', 'no-python-version')
-
-        The warning may also be suppressed on the command line:
-
-            $ scons --warn=no-python-version
-
-        Or by specifying the --warn=no-python-version option in the
-        $SCONSFLAGS environment variable.
-
-        Using SetOption('warn', ...), and the 'no-python-version'
-        command-line option for suppressing this specific warning,
-        are *not* backwards-compatible to earlier versions of SCons.
-
-    --  THE env.Copy() METHOD IS NOW OFFICIALLY DEPRECATED
-
-        The env.Copy() method is now officially deprecated and will
-        be removed in a future release.  Using the env.Copy() method
-        now generates the following message:
-
-            scons: warning: The env.Copy() method is deprecated; use the env.Clone() method instead.
-
-        You may disable all warnings about deprecated features by adding
-        the option "--warn=no-deprecated" to the command line or to the
-        $SCONSFLAGS environment variable:
-
-            $ scons --warn=no-deprecated
-
-        Using '--warn=no-deprecated' is compatible with earlier versions
-        of SCons.
-
-        You may also, as of this version of SCons, disable all warnings
-        about deprecated features by adding the following to any
-        SConscript file:
-
-            SetOption('warn', 'no-deprecated')
-
-	You may disable only the specific warning about the deprecated
-	env.Copy() method by adding the following to any SConscript
-	file:
-
-            SetOption('warn', 'no-deprecated-copy')
-
-        The warning may also be suppressed on the command line:
-
-            $ scons --warn=no-deprecated-copy
-
-        Or by specifying the --warn=no-deprecated-copy option in the
-        $SCONSFLAGS environment variable.
-
-        Using SetOption('warn', ...), and the 'no-deprecated-copy'
-        command-line option for suppressing this specific warning,
-        are *not* backwards-compatible to earlier versions of SCons.
-
-    --  THE --debug=dtree, --debug=stree AND --debug=tree OPTIONS ARE DEPRECATED
-
-        The --debug=dtree, --debug=stree and --debug=tree methods
-        are now officially deprecated and will be removed in a
-        future release.  Using these options now generate a warning
-        message recommending use of the --tree=derived, --tree=all,status
-        and --tree=all options, respectively.
-
-        You may disable these warnings, and all warnings about
-        deprecated features, by adding the option "--warn=no-deprecated"
-        to the command line or to the $SCONSFLAGS environment
-        variable:
-
-            $ scons --warn=no-deprecated
-
-        Using '--warn=no-deprecated' is compatible with earlier versions
-        of SCons.
-
-    --  THE TargetSignatures() AND SourceSignatures() FUNCTIONS ARE DEPRECATED
-
-	The TargetSignatures() and SourceSignatures() functions,
-	and their corresponding env.TargetSignatures() and
-	env.SourceSignatures() methods, are now officially deprecated
-	and will be be removed in a future release.  Using ahy of
-	these functions or methods now generates a message
-	similar to the following:
-
-            scons: warning: The env.TargetSignatures() method is deprecated;
-                    convert your build to use the env.Decider() method instead.
-
-        You may disable all warnings about deprecated features by adding
-        the option "--warn=no-deprecated" to the command line or to the
-        $SCONSFLAGS environment variable:
-
-            $ scons --warn=no-deprecated
-
-        Using '--warn=no-deprecated' is compatible with earlier versions
-        of SCons.
-
-        You may also, as of this version of SCons, disable all warnings
-        about deprecated features by adding the following to any
-        SConscript file:
-
-            SetOption('warn', 'no-deprecated')
-
-	You may disable only the specific warning about the use of
-	TargetSignatures() or SourceSignatures() by adding the
-	following to any SConscript file:
-
-            SetOption('warn', 'no-deprecated-target-signatures')
-            SetOption('warn', 'no-deprecated-source-signatures')
-
-        The warnings may also be suppressed on the command line:
-
-            $ scons --warn=no-deprecated-target-signatures --warn=no-deprecated-source-signatures
-
-	Or by specifying these options in the $SCONSFLAGS environment
-	variable.
-
-	Using SetOption('warn', ...), or the command-line options
-	for suppressing these warnings, is *not* backwards-compatible
-	to earlier versions of SCons.
-
-    --  File(), Dir() and Entry() NOW RETURN A LIST WHEN THE INPUT IS A SEQUENCE
-
-        Previously, if these methods were passed a list, the list was
-        substituted and stringified, then passed as a single string to
-        create a File/Dir/Entry Node.  This rarely if ever worked with
-        more than one element in the list.  They now return a list of
-        Nodes when passed a list.
-
-        One case that works differently now is a passing in a
-        single-element sequence; that formerly was stringified
-        (returning its only element) and then a single Node would be
-        returned.  Now a single-element list containing the Node will
-        be returned, for consistency.
-
-    --  THE env.subst() METHOD NOW RETURNS A LIST WHEN THE INPUT IS A SEQUENCE
-
-        The env.subst() method now returns a list with the elements
-        expanded when given a list as input.  Previously, the env.subst()
-        method would always turn its result into a string.
-
-        This behavior was changed because it interfered with being able
-        to include things like lists within the expansion of variables
-        like $CPPPATH and then have SCons understand that the elements
-        of the "internal" lists still needed to be treated separately.
-        This would cause a $CPPPATH list like ['subdir1', 'subdir']
-        to show up in a command line as "-Isubdir1 subdir".
-
-    --  THE Jar() BUILDER NOW USES THE Java() BUILDER CLASSDIR BY DEFAULT
-
-        By default, the Jar() Builder will now use the class directory
-        specified when the Java() builder is called.  So the following
-        input:
-
-            classes = env.Java('classes', 'src')
-            env.Jar('out.jar', classes)
-
-        Will cause "-C classes" to be passed the "jar" command invocation,
-        and the Java classes in the "out.jar" file will not be prefixed
-        "classes/".
-
-        Explicitly setting the $JARCHDIR variable overrides this default
-        behavior.  The old behavior of not passing any -C option to the
-        "jar" command can be preserved by explicitly setting $JARCHDIR
-        to None:
-
-            env = Environment(JARCHDIR = None)
-
-        The above setting is compatible with older versions of SCons.
-
-  Please note the following important changes since release 0.97.0d20070918:
-
-    --  SCons REDEFINES PYTHON open() AND file() ON Windows TO NOT PASS
-        ON OPEN FILE HANDLES TO CREATED PROCESSES
-
-        On Windows systems, SCons now redefines the Python open()
-        and file() functions so that, if the Python Win32 extensions
-        are available, the file handles for any opened files will *not*
-        be inherited by subprocesses, such as the spawned compilers and
-        other tools invoked to build the software.
-
-        This prevents certain race conditions where a file handle for
-        a file opened by Python (either in a Python function action,
-        or directly in a SConscript file) could be inherited and help
-        open by a subprocess, interfering with the ability of other
-        processes to create or modify the file.
-
-        In general, this should not cause problems for the vast majority
-        of configurations.  The only time this would be a problem would be
-        in the unlikely event that a process spawned by SCons specifically
-        *expected* to use an inherited file handle opened by SCons.
-
-        If the Python Win32 extensions are not installed or are an
-        earlier version that does not have the ability to disable file
-        handle inheritance, SCons will print a warning message when the
-        -j option is used.  The warning message may be suppressed by
-        specifying --warn=no-parallel-support.
-
-  Please note the following important changes since release 0.97.0d20070809:
-
-    --  "content" SIGNATURES ARE NOW THE DEFAULT BEHAVIOR
-
-        The default behavior of SCons is now to use the MD5 checksum of
-        all file contents to decide if any files have changed and should
-        cause rebuilds of their source files.  This means that SCons may
-        decide not to rebuild "downstream" targets if a a given input
-        file is rebuilt to the exact same contents as the last time.
-        The old behavior may preserved by explicity specifying:
-
-            TargetSignatures("build")
-
-        In any of your SConscript files.
-
-    --  TARGETS NOW IMPLICITLY DEPEND ON THE COMMAND THAT BUILDS THEM
-
-        For all targets built by calling external commands (such as a
-        compiler or other utility), SCons now adds an implicit dependency
-        on the command(s) used to build the target.
-
-        This will cause rebuilds of all targets built by external commands
-        when running SCons in a tree built by previous version of SCons,
-        in order to update the recorded signatures.
-
-        The old behavior of not having targets depend on the external
-        commands that build them can be preserved by setting a new
-        $IMPLICIT_COMMAND_DEPENDENCIES construction variable to a
-        non-True value:
-
-            env = Environment(IMPLICIT_COMMAND_DEPENDENCIES = 0)
-        
-        or by adding Ignore() calls for any targets where the behavior
-        is desired:
-
-            Ignore('/usr/bin/gcc', 'foo.o')
-
-        Both of these settings are compatible with older versions
-        of SCons.
-
-    --  CHANGING SourceSignature() MAY CAUSE "UNECESSARY" REBUILDS
-
-        If you change the SourceSignature() value from 'timestamp' to
-        'MD5', SCons will now rebuild targets that were already up-to-date
-        with respect to their source files.
-
-        This will happen because SCons did not record the content
-        signatures of the input source files when the target was last
-        built--it only recorded the timestamps--and it must record them
-        to make sure the signature information is correct.  However,
-        the content of source files may have changed since the last
-        timestamp build was performed, and SCons would not have any way to
-        verify that.  (It would have had to open up the file and record
-        a content signature, which is one of the things you're trying to
-        avoid by specifying use of timestamps....)  So in order to make
-        sure the built targets reflect the contents of the source files,
-        the targets must be rebuilt.
-
-        Change the SourceSignature() value from 'MD5' to 'timestamp'
-        should correctly not rebuild target files, because the timestamp
-        of the files is always recorded.
-
-        In previous versions of SCons, changing the SourceSignature()
-        value would lead to unpredictable behavior, usually including
-        rebuilding targets.
-
-    --  THE Return() FUNCTION NOW ACTUALLY RETURNS IMMEDIATELY
-
-        The Return() function now immediately stops processing the
-        SConscript file in which it appears and returns the values of the
-        variables named in its arguments.  It used to continue processing
-        the rest of the SConscript file, and then return the values of the
-        specified variables at the point the Return() function was called.
-
-        The old behavior may be requested by adding a "stop=False"
-        keyword argument to the Return() call:
-
-                Return('value', stop=False)
-
-        The "stop=" keyword argument is *not* compatible with SCons
-        versions 0.97.0d20070809 or earlier.
-
-  Please note the following important changes since release 0.97:
-
-    --  env.CacheDir() NOW ONLY AFFECTS CONSTRUCTION ENVIRONMENT TARGETS
-
-        The env.CacheDir() method now only causes derived files to be
-        retrieved from the specified cache directory for targets built
-        with the specified specified construction environment ("env").
-
-        Previously, any call to env.CacheDir() or CacheDir() would modify
-        a global setting and cause all built targets to be retrieved
-        from the specified cache directory.  This behavior was changed so
-        that env.CacheDir() would be consistent with other construction
-        environment methods, which only affect targets built with the
-        specified construction environment.
-
-        The old behavior of changing the global behavior may be preserved
-        by changing any env.CacheDir() calls to:
-
-                CacheDir('/path/to/cache/directory')
-
-        The above change is backwards-compatible and works in all earlier
-        versions of SCons that support CacheDir().
-
-    --  INTERPRETATION OF SUFFIX-LESS SOURCE ARGUMENTS HAS CHANGED
-
-        The interpretation of source arguments (files) without suffixes
-        has changed in one specific configuration.
-
-        Previously, if a Builder had a src_suffix specified (indicating
-        that source files without suffixes should have that suffix
-        appended), the suffix would only be applied to suffix-less source
-        arguments if the Builder did *not* have one or more attached
-        source Builders (that is, the Builder was not a "multi-stage"
-        Builder).  So in the following configuration:
-
-                build_foo = Builder(src_suffix = '.foo')
-                build_bar = Builder(src_suffix = '.bar',
-                                    src_builder = build_bar)
-
-                env = Environment(BUILDERS = {
-                                   'Foo' : build_foo,
-                                   'Boo' : build_bar,
-                                  })
-
-                env.Foo('tgt1', 'src1')
-                env.Bar('tgt2', 'src2')
-        
-        SCons would have expected to find a source file 'src1.foo' for the
-        env.Foo() call, but a source file 'src2' for the env.Bar() call.
-
-        This behavior has now been made consistent, so that the two
-        above calls would expect source files named 'src1.foo' and
-        'src2.bar', respectively.
-
-        Note that, if genuinely desired, the old behavior of building
-        from a source file without a suffix at all (when the Builder has
-        a src_suffix *and* a src_builder) can be specified explicity by
-        turning the string into a File Node directly:
-
-                env.Bar('tgt2', File('src2'))
-
-        The above use of File() is backwards-compatible and will work
-        on earlier versions of SCons.
-
-    --  THE DEFAULT EXECUTION PATH FOR Solaris HAS CHANGED
-
-        On Solaris systems, SCons now adds the "/opt/SUNWspro/bin"
-        directory to the default execution $PATH variable before the
-        "/usr/ccs/bin" directory.  This was done to reflect the fact
-        that /opt/SUNWspro/ is the default for SUN tools, but it may
-        cause a different compiler to be used if you have compilers
-        installed in both directories.
-
-    --  GENERATED config.h FILES NOW SAY "#define HAVE_{FEATURE} 1"
-
-        When generating a "config.h" file, SCons now defines values that
-        record the existence of a feature with a "1" value:
-
-            #define HAVE_FEATURE 1
-
-        Instead of printing the line without a "1", as it used to:
-
-            #define HAVE_FEATURE
-
-        This should not cause any problems in the normal use of "#ifdef
-        HAVE_{FEATURE}" statements interpreted by a C preprocessor, but
-        might cause a compatibility issue if a script or other utility
-        looks for an exact match of the previous text.
-
-  Please note the following planned, future changes:
-
-    --  THE Options OBJECT AND RELATED FUNCTIONS WILL BE DEPRECATED
-
-        The Options object is being replaced by a new Variables
-        object, which uses a new Variables.AddVariable() method
-        where the previous interface used Options.AddOptions().
-
-        Similarly, the following utility functions are being replaced
-        by the following similarly-named functions:
-
-                BoolOption()            BoolVariable()
-                EnumOption()            EnumVariable()
-                ListOption()            ListVariable()
-                PackageOption()         PackageVariable()
-                PathOption()            PathVariable()
-
-        And also related, the options= keyword argument when creating
-        construction environments with the Environment() functions is
-        being replaced with a variables= keyword argument.
-
-        In some future release a deprecation warning will be added to
-        existing uses of the Options object, its methods, the above
-        utility functions, and the options= keyword argument of the
-        Environment() function.  At some point after the deprecation
-        warning is added, the Options object, related functions and
-        options= keyword argument will be removed entirely.
-
-        You can prepare for this by changing all your uses of the Options
-        object and related functions to the Variables object and the new
-        function names, and changing any uses of the options= keyword
-        argument to variables=.
-
-        NOTE:  CONVERTING TO USING THE NEW Variables OBJECT OR THE
-        RELATED *Variable() FUNCTIONS, OR USING THE NEW variable=
-        KEYWORD ARGUMENT, IS NOT BACKWARDS COMPATIBLE TO VERSIONS OF
-        SCons BEFORE 0.98.  YOUR SConscript FILES WILL NOT WORK ON
-        EARLIER VERSIONS OF SCons AFTER MAKING THIS CHANGE.
-
-        If you change SConscript files in software that you make available
-        for download or otherwise distribute, other users may try to
-        build your software with an earlier version of SCons that does
-        not have the Variables object or related *Variable() functions.
-        We recommend preparing for this in one of two ways:
-
-            --  Make your SConscript files backwards-compatible by
-                modifying your calls with  Python try:-except: blocks
-                as follows:
-
-                    try:
-                        vars = Variables('custom.py', ARGUMENTS)
-                        vars.AddVariables(
-                            BoolVariable('WARNINGS', 'cmopile with -Wall', 1),
-                            EnumVariable('DEBUG', 'debug version', 'no'
-                                       allowed_values=('yes', 'no', 'full'),
-                                       map={}, ignorecase=0),
-                            ListVariable('SHAREDLIBS',
-                                         'libraries to build shared',
-                                         'all',
-                                         names = list_of_libs),
-                            PackageVariable('X11',
-                                            'use X11 from here',
-                                            '/usr/bin/X11'),
-                            PathVariable('QTDIR', 'root of Qt', qtdir),
-                        )
-                    except NameError:
-                        vars = Options('custom.py', ARGUMENTS)
-                        vars.AddOptions(
-                            BoolOption('WARNINGS', 'cmopile with -Wall', 1),
-                            EnumOption('DEBUG', 'debug version', 'no'
-                                       allowed_values=('yes', 'no', 'full'),
-                                       map={}, ignorecase=0),
-                            ListOption('SHAREDLIBS',
-                                       'libraries to build shared',
-                                       'all',
-                                       names = list_of_libs),
-                            PackageOption('X11',
-                                          'use X11 from here',
-                                          '/usr/bin/X11'),
-                            PathOption('QTDIR', 'root of Qt', qtdir),
-                        )
-
-                Additionally, you can check for availability of the new
-                variables= keyword argument as follows:
-
-                    try:
-                        env = Environment(variables=vars)
-                    except TypeError:
-                        env = Environment(options=vars)
-
-                (Note that we plan to maintain the existing Options object
-                name for some time, to ensure backwards compatibility,
-                so in practice it may be easier to just continue to use
-                the old name until you're reasonably sure you won't have
-                people trying to build your software with versions of
-                SCons earlier than 0.98.1.)
-
-            --  Use the EnsureSConsVersion() function to provide a
-                descriptive error message if your SConscript files
-                are executed by an earlier version of SCons:
-
-                    EnsureSConsVersion(0, 98, 1)
-
-    --  THE BuildDir() METHOD AND FUNCTION WILL BE DEPRECATED
-
-        The env.BuildDir() method and BuildDir() function are being
-        replaced by the new env.VariantDir() method and VariantDir()
-        function.
-
-        In some future release a deprecation warning will be added
-        to existing uses of the env.BuildDir() method and BuildDir()
-        function.  At some point after the deprecation warning, the
-        env.Builder() method and BuildDir() function will either
-        be removed entirely or have their behavior changed.
-
-	You can prepare for this by changing all your uses of the
-	env.BuildDir() method to env.VariantDir() and uses of the
-	global BuildDir() function to VariantDir().  If you use a
-	named keyword argument of "build_dir" when calling
-	env.BuildDir() or BuildDir():
-
-            env.BuildDir(build_dir='opt', src_dir='src')
-
-        The keyword must be changed to "variant_dir":
-
-            env.VariantDir(variant_dir='opt', src_dir='src')
-
-        NOTE:  CHANGING USES OF env.BuildDir() AND BuildDir() to
-        env.VariantDir() AND VariantDir() IS NOT BACKWARDS COMPATIBLE
-        TO VERSIONS OF SCons BEFORE 0.98.  YOUR SConscript FILES
-        WILL NOT WORK ON EARLIER VERSIONS OF SCons AFTER MAKING
-        THIS CHANGE.
-
-        If you change SConscript files in software that you make
-        available for download or otherwise distribute, other users
-        may try to build your software with an earlier version of
-        SCons that does not have the env.VariantDir() method or
-        VariantDir() fnction.  We recommend preparing for this in
-        one of two ways:
-
-            --  Make your SConscript files backwards-compatible by
-                including the following code near the beginning of your
-                top-level SConstruct file:
-
-                    import SCons.Environment
-                    try:
-                        SCons.Environment.Environment.VariantDir
-                    except AttributeError:
-                        SCons.Environment.Environment.VariantDir = \
-                              SCons.Environment.Environment.BuildDir
-
-            --  Use the EnsureSConsVersion() function to provide a
-                descriptive error message if your SConscript files
-                are executed by an earlier version of SCons:
-
-                    EnsureSConsVersion(0, 98)
-
-    --  THE SConscript() "build_dir" KEYWORD ARGUMENT WILL BE DEPRECATED
-
-	The "build_dir" keyword argument of the SConscript function
-	and env.SConscript() method are being replaced by a new
-	"variant_dir" keyword argument.
-
-	In some future release a deprecation warning will be added
-	to existing uses of the SConscript()/env.SConscript()
-	"build_dir" keyword argument.  At some point after the
-	deprecation warning, support for this keyword argument will
-	be removed entirely.
-
-	You can prepare for this by changing all your uses of the
-	SConscript()/env.SConscript() 'build_dir" keyword argument:
-
-            SConscript('src/SConscript', build_dir='opt')
-
-        To use the new "variant_dir" keyword argument:
-
-            SConscript('src/SConscript', variant_dir='opt')
-
-	NOTE:  USING THE NEW "variant_dir" KEYWORD IS NOT BACKWARDS
-	COMPATIBLE TO VERSIONS OF SCons BEFORE 0.98.  YOUR SConscript
-	FILES WILL NOT WORK ON EARLIER VERSIONS OF SCons AFTER
-	MAKING THIS CHANGE.
-
-	If you change SConscript files in software that you make
-	available for download or otherwise distribute, other users
-	may try to build your software with an earlier version of
-	SCons that does not support the "variant_dir" keyword.
-
-	If you can insist that users use a recent version of SCons
-	that supports "variant_dir", we recommend using the
-	EnsureSConsVersion() function to provide a descriptive error
-	message if your SConscript files are executed by an earlier
-	version of SCons:
-
-                    EnsureSConsVersion(0, 98)
-
-	If you want to make sure that your SConscript files will
-	still work with earlier versions of SCons, then your best
-	bet is to continue to use the "build_dir" keyword until the
-	support is removed (which, in all likelihood, won't happen
-	for quite some time).
-
-    --  SCANNER NAMES HAVE BEEN DEPRECATED AND WILL BE REMOVED
-
-        Several internal variable names in SCons.Defaults for various
-        pre-made default Scanner objects have been deprecated and will
-        be removed in a future revision.  In their place are several new
-        global variable names that are now part of the publicly-supported
-        interface:
-
-            NEW NAME              DEPRECATED NAME
-            --------              ----------------------------
-            CScanner              SCons.Defaults.CScan
-            DSCanner              SCons.Defaults.DScan
-            SourceFileScanner     SCons.Defaults.ObjSourceScan
-            ProgramScanner        SCons.Defaults.ProgScan
-
-        Of these, only ObjSourceScan was probably used at all, to add
-        new mappings of file suffixes to other scanners for use by the
-        Object() Builder.  This should now be done as follows:
-
-            SourceFileScanner.add_scanner('.x', XScanner)
-
-    --  THE env.Copy() METHOD WILL CHANGE OR GO AWAY ENTIRELY
-
-        The env.Copy() method (to make a copy of a construction
-        environment) is being replaced by the env.Clone() method.
-
-        As of SCons 0.98, a deprecation warning has been added to
-        current uses of the env.Copy() method.  At some point in
-        the future, the env.Copy() method will either be removed
-        entirely or have its behavior changed.
-
-        You can prepare for this by changing all your uses of env.Copy()
-        to env.Clone(), which has the exact same calling arguments.
-
-        NOTE:  CHANGING USES OF env.Copy() TO env.Clone() WILL MAKE
-        YOUR SConscript FILES NOT WORK ON VERSIONS OF SCons BEFORE
-        0.96.93.
-
-        If you change SConscript files in software that you make
-        available for download or otherwise distribute, other users
-        may try to build your software with an earlier version of
-        SCons that does not have the env.Clone() method.  We recommend
-        preparing for this in one of two ways:
-
-            --  Make your SConscript files backwards-compatible by
-                including the following code near the beginning of your
-                top-level SConstruct file:
-
-                    import SCons.Environment
-                    try:
-                        SCons.Environment.Environment.Clone
-                    except AttributeError:
-                        SCons.Environment.Environment.Clone = \
-                              SCons.Environment.Environment.Copy
-
-            --  Use the EnsureSConsVersion() function to provide a
-                descriptive error message if your SConscript files
-                are executed by an earlier version of SCons:
-
-                    EnsureSConsVersion(0, 96, 93)
-
-    --  THE CheckLib Configure TEST WILL CHANGE BEHAVIOR
-
-    	The CheckLib() Configure test appends the lib(s) to the
-    	Environment's LIBS list in 1.3 and earlier.  In 1.3 there is a
-    	new CheckLib argument, append, which defaults to True to
-    	preserve the old behavior.  In a future release, append will
-    	be changed to default to False, to conform with autoconf and
-    	user expectations, since it is usually used to build up
-    	library lists in a right-to-left way.
-
-
-
-  SCons is developed with an extensive regression test suite, and a
-  rigorous development methodology for continually improving that suite.
-  Because of this, SCons is of sufficient quality that you can use it
-  for real work.
-
-  The interfaces in release 1.0 will *not* be knowingly changed in
-  any new, future 1.x release.  If an interface change should ever
-  become necessary due to extraordinary circumstances, the change
-  and an appropriate transition strategy will be documented in these
-  RELEASE notes.
-
-  As you use SCons, please heed the following:
-
-    - Please report any bugs or other problems that you find to our bug
-      tracker at our SourceForge project page:
-
-      http://sourceforge.net/tracker/?func=add&group_id=30337&atid=398971
-
-      We have a reliable bug-fixing methodology already in place and
-      strive to respond to problems relatively quickly.
-
-    - Documentation is spottier than we'd like.  You may need to dive
-      into the source code to figure out how to do something.  Asking
-      questions on the scons-users mailing list is also welcome.  We
-      will be addressing the documentation in upcoming releases, but
-      would be more than glad to have your assistance in correcting this
-      problem... :-)
-
-    - The "SCons Design" documentation on the SCons web site is very
-      out of date, as we made significant changes to portions of the
-      interface as we figured out what worked and what didn't during the
-      extensive beta implementation.  The "SCons Design" document should
-      be used only for historical purposes, or for just an extremely
-      general understanding of SCons' architectural goals.
-
-    - There may be performance issues.  Improving SCons performance
-      is an ongoing priority.  If you still find the performance
-      unacceptable, we would very much like to hear from you and learn
-      more about your configuration so we can optimize the right things.
-
-    - Error messages don't always exist where they'd be helpful.
-      Please let us know about any errors you ran into that would
-      have benefitted from a (more) descriptive message.
-
-  KNOWN PROBLEMS IN THIS RELEASE:
-
-    For a complete list of known problems, consult the SCons Issue Tracker
-    at tigris.org:
-
-        http://scons.tigris.org/project_issues.html
-
-    - Support for parallel builds (-j) does not work on WIN32 systems
-      prior to *official* Python release 2.2 (not 2.2 pre-releases).
-
-      Prior to Python 2.2, there is a bug in Python's Win32
-      implementation such that when a thread spawns an external command,
-      it blocks all threads from running.  This breaks the SCons
-      multithreading architecture used to support -j builds.
-
-      We have included a patch file, os_spawnv_fix.diff, that you can
-      use if you you want to fix your version of Python to support
-      parallel builds in SCons.
-
-    - Again, the "SCons Design" documentation on the SCons web site is
-      out of date.  Take what you read there with a grain of salt.
-
-    - On Win32 systems, you must put a space between the redirection
-      characters < and >, and the specified files (or construction
-      variable expansions):
-
-        command < $SOURCE > $TARGET
-
-      If you don't supply a space (for example, "<$SOURCE"), SCons will
-      not recognize the redirection.
-
-    - MSVC .res files are not rebuilt when icons change.
-
-    - The -c option does not clean up .sconsign files or directories
-      created as part of the build, and also does not clean up
-      SideEffect files (for example, Visual Studio .pdb files).
-
-    - When using multiple Repositories, changing the name of an include
-      file can cause an old version of the file to be used.
-
-    - There is currently no way to force use of a relative path (../*)
-      for directories outside the top-level SConstruct file.
-
-    - The Jar() Builder will, on its second or subsequent invocation,
-      package up the .sconsign files that SCons uses to track signatures.
-      You can work around this by using the SConsignFile() function
-      to collect all of the .sconsign information into a single file
-      outside of the directory being packaged by Jar().
-
-    - SCons does not currently have a way to detect that an intermediate
-      file has been corrupted from outside and should be rebuilt.
-
-    - Unicode characters in path names do not work in all circumstances.
-
-    - SCons does not currently automatically check out SConstruct or
-      SConscript files from SCCS, RCS or BitKeeper.
-
-    - No support yet for the following planned command-line options:
-
-         -d -e -l --list-actions --list-derived --list-where
-         -o --override -p -r -R -w --write-filenames
-         -W --warn-undefined-variables
-
-
-
-Thank you for your interest, and please let us know how we can help
-improve SCons for your needs.
-
-Steven Knight
-knight at baldmt dot com
-http://www.baldmt.com/~knight/
-
-With plenty of help from the SCons Development team:
-        Chad Austin
-        Charles Crain
-        Bill Deegan
-        Steve Leblanc
-        Greg Noel
-        Gary Oberbrunner
-        Anthony Roach
-        Greg Spencer
-        Christoph Wiedemann
+  Thanks to Greg Noel, Steven Knight, Dirk Baechle, William Deegan,and 
+  W. Trevor King for their contributions to this release.
 
+Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 The SCons Foundation
+src/RELEASE.txt 5023 2010/06/14 22:05:46 scons