test-obsolete: use 'log -T {node}' instead of 'id --debug -i' to lookup hash
I ran into a case when adding a test where there were cryptic hg command line
errors. I eventually traced it back to 'hg id' printing debug messages before
the hash:
invalid branchheads cache (served): tip differs <hash>
This method should eliminate any other output except the node.
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24
$ cd ..