Flush stderr after write.
stderr can be buffered under win32 when redirected to a file,
including stdout.
adding foo
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
foo
2ed2a3912a0b24502043eae84ee4b279c18b90dd 644 foo
pulling from http://localhost:20059/
searching for changes
no changes found