When removing the hack for isatty(), we actually removed more than just an isatty() hack: we removed the hack where internal data structures of the MSVC runtime are modified in order to redirect stdout/stderr. Instead of using that hack (that does not work with newer versions of the runtime, anyway), we replaced it by reopening the respective file descriptors. What we forgot was to mark stderr as unbuffered again. Reported by Hannes Sixt. Fixed with Jeff Hostetler's assistance. Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx> --- Published-As: https://github.com/dscho/git/releases/tag/mingw-unbuffered-stderr-v1 Fetch-It-Via: git fetch https://github.com/dscho/git mingw-unbuffered-stderr-v1 compat/winansi.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/compat/winansi.c b/compat/winansi.c index 82b89ab1376..793420f9d0d 100644 --- a/compat/winansi.c +++ b/compat/winansi.c @@ -510,6 +510,8 @@ static HANDLE swap_osfhnd(int fd, HANDLE new_handle) */ close(new_fd); + if (fd == 2) + setvbuf(stderr, NULL, _IONBF, BUFSIZ); fd_is_interactive[fd] |= FD_SWAPPED; return duplicate; @@ -547,6 +549,8 @@ static void detect_msys_tty(int fd) !wcsstr(name, L"-pty")) return; + if (fd == 2) + setvbuf(stderr, NULL, _IONBF, BUFSIZ); fd_is_interactive[fd] |= FD_MSYS; } base-commit: 5588dbffbd61e4906e453808c6ad32f792fea521 -- 2.11.1.windows.1