apenwarr-redo/t/360-symlinks/b.do

printf x >>b.ran
redo-ifchange a
cat a >$3 || :
Further improve handling of symlink targets/deps. In commit redo-0.11-4-g34669fb, we changed os.stat into os.lstat to avoid false positives in the "manual override" detector: a .do file that generates $3 as a symlink would trigger manual override if the target of that symlink ever changed, which is incorrect. Unfortunately using os.lstat() leads to a different problem: if X depends on Y and Y is a symlink to Z, then X would not be rebuilt when Z changes, which is clearly wrong. The fix is twofold: 1. read_stamp() should change on changes to both the link itself, and the target of the link. 2. We shouldn't mark a target as overridden under so many situations. We'll use only the primary mtime of the os.lstat(), not all the other bits in the stamp. Step 2 fixes a few other false positives also. For example, if you 'cp -a' a whole tree to another location, the st_ino of all the targets will change, which would trigger a mass of "manual override" warnings. Although a change in inode is sufficient to count an input as having changed (just to be extra safe), it should not be considered a manual override. Now we can distinguish between the two. Because the stamp format has changed, update the SCHEMA_VER field. I should have done this every other time I changed the stamp format, but I forgot. Sorry. That leads to spurious "manually modified" warnings after upgrading redo. 2018-11-21 07:19:20 -05:00			`printf x >>b.ran`
Use os.lstat() instead of os.stat(). I think this aligns better with how redo works. Otherwise, if a.do creates a as a symlink, then changes to the symlink's target will change a's stat/stamp information without re-running a.do, which looks to redo like you modified a by hand, which causes it to stop running a.do altogether. With this change, modifications to a's target are okay, but they don't trigger any redo dependency changes. If you want that, then a.do should redo-ifchange on its symlink target explicitly. 2018-10-06 00:14:02 -04:00			`redo-ifchange a`
Further improve handling of symlink targets/deps. In commit redo-0.11-4-g34669fb, we changed os.stat into os.lstat to avoid false positives in the "manual override" detector: a .do file that generates $3 as a symlink would trigger manual override if the target of that symlink ever changed, which is incorrect. Unfortunately using os.lstat() leads to a different problem: if X depends on Y and Y is a symlink to Z, then X would not be rebuilt when Z changes, which is clearly wrong. The fix is twofold: 1. read_stamp() should change on changes to both the link itself, and the target of the link. 2. We shouldn't mark a target as overridden under so many situations. We'll use only the primary mtime of the os.lstat(), not all the other bits in the stamp. Step 2 fixes a few other false positives also. For example, if you 'cp -a' a whole tree to another location, the st_ino of all the targets will change, which would trigger a mass of "manual override" warnings. Although a change in inode is sufficient to count an input as having changed (just to be extra safe), it should not be considered a manual override. Now we can distinguish between the two. Because the stamp format has changed, update the SCHEMA_VER field. I should have done this every other time I changed the stamp format, but I forgot. Sorry. That leads to spurious "manually modified" warnings after upgrading redo. 2018-11-21 07:19:20 -05:00			`cat a >$3 \|\| :`