Warn about orphan .git directories

[jaydoane]

Overview

A .git directory found in src/ usually indicates that the code in the
enclosing directory is managed from said .git directory. This can lead
to confusion, and developers opening PRs against obsolete repos when, as
happens frequently, a formerly separate repository becomes integrated
into the primary repo.

This patch changes the configure script to warn when it finds such .git
directories.

Testing recommendations

Example output:

$ ./configure --dev --skip-deps
==> configuring couchdb in rel/couchdb.config
WARNING unexpected .git directory src/couch_tests/.git
WARNING unexpected .git directory src/rexi/.git
WARNING unexpected .git directory src/mem3/.git
WARNING unexpected .git directory src/smoosh/.git
WARNING unexpected .git directory src/couch_mrview/.git
WARNING unexpected .git directory src/couch/.git
WARNING unexpected .git directory src/couch_replicator/.git
WARNING unexpected .git directory src/ddoc_cache/.git
WARNING unexpected .git directory src/couch_peruser/.git
WARNING unexpected .git directory src/setup/.git
WARNING unexpected .git directory src/couch_log/.git
WARNING unexpected .git directory src/couch_epi/.git
WARNING unexpected .git directory src/mango/.git
WARNING unexpected .git directory src/chttpd/.git
WARNING unexpected .git directory src/couch_stats/.git
WARNING unexpected .git directory src/global_changes/.git
WARNING unexpected .git directory src/couch_event/.git
WARNING unexpected .git directory src/fabric/.git
WARNING unexpected .git directory src/couch_plugins/.git
WARNING unexpected .git directory src/ken/.git
WARNING unexpected .git directory src/couch_index/.git
You have configured Apache CouchDB, time to relax. Relax.

Related Issues or Pull Requests

Checklist

• Code is written and works correctly
• Changes are covered by tests
• Any new configurable parameters are documented in rel/overlay/etc/default.ini
• A PR for documentation changes has been made in https://github.com/apache/couchdb-documentation

[davisp]

I'm on board with this other than making it conditional. I'd remove the toggle and just run it regardless as it seems like good hygiene for those of us that skip around between major versions fairly often.

Though that also assumes that its not super expensive though it doesn't look like it would be.

[jaydoane]

@davisp I originally did write it without the conditional, but became concerned about forcing a potentially expensivefind (which I've since improved on by adding -type dir) on everyone each time it was run. Maybe more worrisome though, I'm not sure find is available on Windows, so it seemed best to make it optional, but figured adding it to make dev would probably hit most use cases.

[davisp]

Windows uses the configure.ps1 command thingamajig so that shouldn't be an issue (cc @wohali). For the expensiveness I'm not overly concerned. But if you like then only adding it to --dev seems fine. I don't really see it useful as a standalone option cause I don't think it'd be an issue often enough to really get into muscle memory.

[jaydoane]

Great, let's make it non-optional since it's simpler.

[davisp]

+1 but squash those into a single commit.