renameByCopy: retry os.RemoveAll

[judwhite]

What does this do / why do we need it?

Was receiving this consistently, always with the same directory:

grouped write of manifest, lock and vendor:
     cannot delete /tmp/dep152972340/vendor:
     remove /tmp/dep152972340/vendor/golang.org/x/sys/unix:
     directory not empty

A simple retry corrected the issue, consistently.

This was on the Windows 10 Linux subsystem, FWIW, where GOOS=linux/amd64. windows/amd64 and linux/amd64 on TravisCI did not encounter this issue.

Maybe chalk this up to the Windows' Linux subsystem being beta.

If you want this patch I'll drop a comment about why there's a retry and update the CHANGELOG.

The confusing thing for me while debugging was the defer os.RemoveAll(dir) succeeded, so I could never find the files it said it couldn't delete; it was essentially retrying in the defer and succeeding.

Before:

jwhite@Jud-I7:/mnt/d/Projects/_go/src/github.com/nsqio/nsq$ dep ensure -v
Gopkg.lock was already in sync with imports and Gopkg.toml
(1/12) Wrote github.com/bitly/timer_metrics@afad1794bb13e2a094720aeb27c088aa64564895
(2/12) Wrote github.com/mreiferson/go-options@77551d20752b54535462404ad9d877ebdb26e53d
(3/12) Wrote github.com/nsqio/go-diskqueue@0681a1afee1245efa503b7543989fc26d8f268bc
(4/12) Wrote github.com/judwhite/go-svc@63c12402f579f0bdf022653c821a1aa5d7544f01
(5/12) Wrote github.com/bitly/go-hostpool@58b95b10d6ca26723a7f46017b348653b825a8d6
(6/12) Wrote github.com/julienschmidt/httprouter@6aacfd5ab513e34f7e64ea9627ab9670371b34e7
(7/12) Wrote github.com/bmizerany/perks@6cb9d9d729303ee2628580d9aec5db968da3a607
(8/12) Wrote github.com/golang/snappy@d9eb7a3d35ec988b8585d4a0068e462c27d28380
(9/12) Wrote github.com/blang/semver@9bf7bff48b0388cb75991e58c6df7d13e982f1f2
(10/12) Wrote github.com/BurntSushi/toml@2dff11163ee667d51dcc066660925a92ce138deb
(11/12) Wrote github.com/nsqio/go-nsq@a53d495e81424aaf7a7665a9d32a97715c40e953
(12/12) Wrote golang.org/x/sys@master
grouped write of manifest, lock and vendor: cannot delete /tmp/dep152972340/vendor: remove /tmp/dep152972340/vendor/golang.org/x/sys/unix: directory not empty

After:

jwhite@Jud-I7:/mnt/d/Projects/_go/src/github.com/nsqio/nsq$ dep ensure -v
Gopkg.lock was already in sync with imports and Gopkg.toml
(1/12) Wrote github.com/golang/snappy@d9eb7a3d35ec988b8585d4a0068e462c27d28380
(2/12) Wrote github.com/blang/semver@9bf7bff48b0388cb75991e58c6df7d13e982f1f2
(3/12) Wrote github.com/bitly/timer_metrics@afad1794bb13e2a094720aeb27c088aa64564895
(4/12) Wrote github.com/julienschmidt/httprouter@6aacfd5ab513e34f7e64ea9627ab9670371b34e7
(5/12) Wrote github.com/bitly/go-hostpool@58b95b10d6ca26723a7f46017b348653b825a8d6
(6/12) Wrote github.com/nsqio/go-diskqueue@0681a1afee1245efa503b7543989fc26d8f268bc
(7/12) Wrote github.com/bmizerany/perks@6cb9d9d729303ee2628580d9aec5db968da3a607
(8/12) Wrote github.com/mreiferson/go-options@77551d20752b54535462404ad9d877ebdb26e53d
(9/12) Wrote github.com/BurntSushi/toml@2dff11163ee667d51dcc066660925a92ce138deb
(10/12) Wrote github.com/nsqio/go-nsq@a53d495e81424aaf7a7665a9d32a97715c40e953
(11/12) Wrote github.com/judwhite/go-svc@63c12402f579f0bdf022653c821a1aa5d7544f01
(12/12) Wrote golang.org/x/sys@master

What should your reviewer look out for in this PR?

Is there a less ugly way?

Do you need help or clarification on anything?

See above 😄

Which issue(s) does this PR fix?

I went through the open issues. It's most closely related to #82, but not exactly.

[ibrasho]

Did you check #1091? I think we found that the reason is related to BashOnWindows.

[judwhite]

@ibrasho Thanks, that exactly describes it. #1136 and microsoft/WSL#2077 add more info.

If there a lot of people impacted it might be worth considering until the update hits RTM; otherwise it's probably not in anyone's interest to work around OS bugs which will be fixed soon and I'm happy to close. Maybe a note in the docs for WSL users that they really have no recourse for this issue.

[judwhite]

@sdboyer Worth working this into a more fail-safe version or close?

[judwhite]

This seems unneeded. If anyone runs into this issue you can get Windows 10 Fall Creators Update here: https://www.microsoft.com/en-us/software-download/windows10