x/build/maintner: git: argument list too long

[AlekSi]

$ maintnerd -config=go -debug
[…]
2017/05/28 15:25:28 gerrit go.googlesource.com/go: git directory exists.
2017/05/28 15:25:28 gerrit go.googlesource.com/go: fixing indexing of 20806 missing commits
2017/05/28 15:25:28 gerrit go.googlesource.com/go: fetching 20806 hashes...
2017/05/28 15:25:29 error fetching 20806 hashes from gerrit project go.googlesource.com/go:
2017/05/28 15:25:29 gerrit go.googlesource.com/go: sync: fork/exec /usr/local/bin/git: argument list too long
2017/05/28 15:25:29 IS TEMP ERROR? *os.PathError fork/exec /usr/local/bin/git: argument list too long
2017/05/28 15:25:29 Temporary error from gerrit go.googlesource.com/go: fork/exec /usr/local/bin/git: argument list too long

I hacked code a little to add logging and found that git fetch is really called with 20k hashes:

fetch --quiet origin b3f1dfd7e02b0685f87572d536742300140ed8ee 634af4c052f9570ce59a377bf83b760b28a1d33d […]

I guess syncMissingCommits should use batches too. Maybe batching should be moved from syncOnce to fetchHashes.

[AlekSi]

I don't think this is a problem anymore. @bradfitz please correct me if I'm wrong.

[bradfitz]

@AlekSi, I don't remember fixing this, so I'm not sure. But I also never this problem, and 2-3 other people setup maintner for their projects and didn't report hitting this, so maybe it got fixed.