On systems where 'python' refers to python3, redo
failed to launch. All invocations of python have been
made explicitly python2 invocations. All tests pass
on an Arch Linux system as of this commit.
This happens sometimes, for example, if you do
whatever | while read x; do
redo-ifchange "$x"
done
and the input contains blank lines.
We could ignore the request for blankness, but it seems like that
situation might indicate a more serious bug in your parser, so it's
probably better to just abort with a meaningful error.
It passes all tests when run serialized, but still gives weird errors
(OperationalError: database is locked) when run with -j5. sqlite3 shouldn't
be barfing just because the database is locked, since the default timeout is
5 seconds, and it's dying *way* faster than that.
Again, I forgot to make vars.py not crash if the variables aren't set, so we
can print a useful error message. But this time I have the right solution:
vars.py will do the checking for itself, and abort with a nice message.
This doesn't really seem to change anything, but it's more correct and
should reveal weirdness (especially an incorrect .redo directory in a
sub-redo) sooner.
I'm pretty sure this must be the intended behaviour. It's kind of
meaningless to use this to declare a dependency on a file that might start
to exist later, if the file already exists.
