fix error on AppVeyor

[mattn]

As far as I can see, It seeks git.exe call fork(2) to do something about ls-remote or git-remote-http on Windows. But it often quit without waiting the child process. So the git.exe hold the handle of directory which should be removed. This occured while removing temporary directory in tg.cleanup. I don't know how to fix this git process. For example:

diff --git a/dep_test.go b/dep_test.go
index ecec35f..9f518be 100644
--- a/dep_test.go
+++ b/dep_test.go
@@ -16,6 +16,7 @@ import (
 	"runtime"
 	"strings"
 	"testing"
+	"time"
 )
 
 var (
@@ -483,8 +484,16 @@ func (tg *testgoData) cleanup() {
 		tg.check(os.RemoveAll(path))
 	}
 	if tg.tempdir != "" {
-		exec.Command(`taskkill`, `/F`, `/IM`, `git.exe`).Run()
-		tg.check(os.RemoveAll(tg.tempdir))
+		if runtime.GOOS == "windows" {
+			for {
+				if os.RemoveAll(tg.tempdir) == nil {
+					break
+				}
+				time.Sleep(time.Second)
+			}
+		} else {
+			tg.check(os.RemoveAll(tg.tempdir))
+		}
 	}
 }

Waiting something (maybe git.exe) fixes this issue. But no reason to wait the bad child. Then, terminate all git.exe in tg.This patch should work.

[mattn]

Yes, 💚 https://ci.appveyor.com/project/jessfraz/dep/build/39

[zchee]

@mattn Thanks fixed, and I totally understand why AppVeyor failed.
It seems good to merge my #156 after merging this PR.

[sdboyer]

oh, awesome! i think i've run into similar issues in the past in gps. there isn't the same kind of testing harness in gps as dep has (though maybe there should be), so it's not as central of a fix as this. still, though, it would be great to adapt this to over there.

i'm going to wait on this until we can get those travis failures fixed, though. hopefully #156 will do that for us.

[mattn]

This should treat parallel tests. So please wait.

[mattn]

still bad

[jessfraz]

ya this was super racey before it would fail like 40% of the time but i'd just rebuild, thanks for putting the time into fixing this :)

[sdboyer]

i don't know why travis can't get its act together 😡

[sdboyer]

Whatever, it works on appveyor - that's the only place where a change actually occurred.

[mattn]

Thank you. I just figure out what process hold the handle of the directory. handle command from sysinternal is very useful to do.

https://technet.microsoft.com/en-us/sysinternals

------------------------------------------------------------------------------
git.exe pid: 14016 XXXXXXXXXXXX
   68: Section       \BaseNamedObjects\msys-2.0S5-dd50a72ab4668b33\shared.5
   6C: Section       \BaseNamedObjects\msys-2.0S5-dd50a72ab4668b33\S-1-5-21-1292428093-1004336348-682003330-12675.1
   98: File  (---)   C:\Users\mattn\AppData\Local\Temp\gotest538495084\src\github.com\golang\notexist
   A8: Section       \BaseNamedObjects\msys-2.0S5-dd50a72ab4668b33\cygpid.14016