This can happen when $PWD contains a symlink somewhere in the path. In
that case, "cd ..; cat x" could mean something different from "cat ../x".
Notably, this error occurs when running "./do test" if your build
directory is through a symlink. For example, on freebsd your home
directory is /home/$USER, but /home is a symlink to /usr/home, which
triggers this problem.
Not adding tests in this commit, because when I added some tests, I
found even more symlink-related bugs, but those ones are much more
unlikely to occur. The additional fixes+tests are in a later commit.
It's time to start preparing for a version of redo that doesn't work
unless we build it first (because it will rely on C modules, and
eventually be rewritten in C altogether).
To get rolling, remove the old-style symlinks to the main programs, and
rename those programs from redo-*.py to redo/cmd_*.py. We'll also move
all library functions into the redo/ dir, which is a more python-style
naming convention.
Previously, install.do was generating wrappers for installing in
/usr/bin, which extend sys.path and then import+run the right file.
This made "installed" redo work quite differently from running redo
inside its source tree. Instead, let's always generate the wrappers in
bin/, and not make anything executable except those wrappers.
Since we're generating wrappers anyway, let's actually auto-detect the
right version of python for the running system; distros can't seem to
agree on what to call their python2 binaries (sigh). We'll fill in the
right #! shebang lines. Since we're doing that, we can stop using
/usr/bin/env, which will a) make things slightly faster, and b) let us
use "python -S", which tells python not to load a bunch of extra crap
we're not using, thus improving startup times.
Annoyingly, we now have to build redo using minimal/do, then run the
tests using bin/redo. To make this less annoying, we add a toplevel
./do script that knows the right steps, and a Makefile (whee!) for
people who are used to typing 'make' and 'make test' and 'make clean'.
