Git without morning coffee

Is this my lack of morning coffee, or git's:

git rev-parse origin/next origin/pu 7931f38a2fd882b0f75a4d6f0eb60c3b1b094178 edf014b39ded8ee8a67f2a0cd8d7926b33f3d578 # OK

git checkout origin/next HEAD is now at 7931f38... Merge branch 'master' into next # OK

git log --oneline --no-walk ":/Merge branch 'jk/generation-numbers' into pu" 0ac76f9 Merge branch 'jk/generation-numbers' into pu # Sure it is.

git merge ":/Merge branch 'jk/generation-numbers' into pu" fatal: ':/Merge branch 'jk/generation-numbers' into pu' does not point to a commit # Huh?

git rev-parse ":/Merge branch 'jk/generation-numbers' into pu" 0ac76f96a94a46bce7ec9dcc6c67abcf9d36adac # It does point to a commit!

git merge $(git rev-parse ":/Merge branch 'jk/generation-numbers' into pu") error: addinfo_cache failed for path 't/t7810-grep.sh' Performing inexact rename detection: 100% (91476/91476), done. error: addinfo_cache failed for path 't/t7810-grep.sh' error: addinfo_cache failed for path 'gitweb/static/gitweb.js' error: addinfo_cache failed for path 'gitweb/static/gitweb.css'

## hundreds more

error: addinfo_cache failed for path 't/t7810-grep.sh' error: addinfo_cache failed for path 'gitweb/static/js/blame_incremental.js' Auto-merging cache.h Merge made by the 'recursive' strategy.

Double Huh? Finally, the merge succeeds, despite thy myriad of errors.

I mean, I'm merging a commit from origin/pu to origin/next when the latter is basically contained in the former (except for some merge commits). And what are these addinfo_cache errors?

git --version git version 1.7.7.rc0.328.g9d6c7

which is last week's next with a few additions which I've been carrying along for weeks. Stumped.

Michael