[Scons-users] strange behavior with path as an array

[robert zeigler]

I think I've uncovered an scons bug (or at least a not-well-documented
"feature").

The following simple build script demonstrates the issue:

path=['/usr/local/bin:/opt/bin:/bin:/usr/bin'] #<-- this is the problematic
line. See below.

DefaultEnvironment(ENV={'PATH': path})

Command("A", "", "echo 'This is A' > $TARGET")
Command("B", "A", "cp $SOURCE $TARGET")
Command("C", "A", "cp $SOURCE $TARGET")


Running the first time gives:

scons: Reading SConscript files ...
scons: done reading SConscript files.
scons: Building targets ...
echo 'This is A' > A
cp A B
cp A C
scons: done building targets.

Next, running scons -n --debug=explain says:

scons: Reading SConscript files ...
scons: done reading SConscript files.
scons: Building targets ...
scons: rebuilding `B' because `/bin/cp' is no longer a dependency
cp A B
scons: rebuilding `C' because `/bin/cp' is no longer a dependency
cp A C
scons: done building targets.


But running scons does:

scons: Reading SConscript files ...
scons: done reading SConscript files.
scons: Building targets ...
cp A B
scons: done building targets.


And running it again does:

scons: Reading SConscript files ...
scons: done reading SConscript files.
scons: Building targets ...
cp A C
scons: done building targets.

Subsequent invocations of scons results in  scons reporting . is up to date.

The problem is this line:

path=['/usr/local/bin:/opt/bin:/bin:/usr/bin']

If it is specified as:

path='/usr/local/bin:/opt/bin:/bin:/usr/bin'

Or as:

path=['/usr/local/bin', '/opt/bin', '/bin', '/usr/bin']

Everything works as expected.

What I consider a bug in scons is:
1) The build works the first time, but subsequent builds don't. I would
expect scons to either fail consistently or succeed consistently.
2) A dry run and a "real" run result in two different behaviors.

Robert
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