I too have noticed this problem or a variation of it. I've narrowed it down to the change in pipe behavior in snapshot cygwin-src-20111023
Specifically in http://cygwin.com/snapshots/winsup-diffs-20111022-20111023 + Note that the write side of the pipe is opened as PIPE_TYPE_MESSAGE. + This *seems* to more closely mimic Linux pipe behavior and is + definitely required for pty handling since fhandler_pty_master + writes to the pipe in chunks, terminated by newline when CANON mode + is specified. */ r = CreateNamedPipe (pipename, PIPE_ACCESS_INBOUND | overlapped, - PIPE_TYPE_BYTE | PIPE_READMODE_BYTE, 1, psize, + PIPE_TYPE_MESSAGE | PIPE_READMODE_BYTE, 1, psize, I took a copy of the 20111023 snapshot source and compiled cygwin1.dll, copied it to cygwin1.dll-message, patched the source back to the PIPE_TYPE_BYTE, recompiled and copied cygwin1.dll to cygwin1.dll-byte. Running a sample test case (attached), the output from any .NET application that I tried (eg MSBuild.exe) caused the pipe to close and I'd get no output. Non .NET applications like "cmd.exe /c ver" worked fine with both dlls. Importantly for me, if a program such as make is called where the MSBuild.exe is called from the Makefile not only is there no output from the MSBuild.exe command but the entire command tree resulting from the pipe exits immediately without any error or exception. Workarounds in the other posts to get the .NET application to even run including piping the output to another command loses the return code from the application or the output. My current workaround of recompiling cygwin1.dll from source with PIPE_TYPE_BYTE currently seems to work but it's probably going to cause other problems further down the line as this patch included some explanatory text stating why it is necessary. Regards David
safeopen.pl
Description: Binary data
===== Incorrect Output =====
C:\cygwin\bin>copy cygwin1.dll-message cygwin1.dll
Overwrite cygwin1.dll? (Yes/No/All): y
1 file(s) copied.
build@build06 ~
$ perl safeopen.pl
Running command: /cygdrive/c/WINDOWS/Microsoft.NET/Framework/v3.5/MSBuild.exe -v
ersion
Running command: /cygdrive/c/WINDOWS/SYSTEM32/cmd.exe /c ver
Microsoft Windows XP [Version 5.1.2600]
build@build06 ~
$ exit
===== Correct Output =====
C:\cygwin\bin>copy cygwin1.dll-byte cygwin1.dll
Overwrite cygwin1.dll? (Yes/No/All): y
1 file(s) copied.
build@build06 ~
$ perl safeopen.pl
Running command: /cygdrive/c/WINDOWS/Microsoft.NET/Framework/v3.5/MSBuild.exe -v
ersion
Microsoft (R) Build Engine Version 3.5.30729.1
[Microsoft .NET Framework, Version 2.0.50727.3625]
Copyright (C) Microsoft Corporation 2007. All rights reserved.
3.5.30729.1
Running command: /cygdrive/c/WINDOWS/SYSTEM32/cmd.exe /c ver
Microsoft Windows XP [Version 5.1.2600]
build@build06 ~
$ exit
-- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
