> -----Original Message----- > Sent: Friday, June 22, 2012 19:11 > Subject: Re: stdout not visible on some programs after upgrading from to > 1.7.11-1 to 1.7.15-1 > > >> I use cygwin on a windows 7 machine to automate a Visual Studio 10 > >> build from the command line. To do this, I invoke MSBuild.exe with a > >> wrapper script called msbuild.sh (see below). Under cygwin 1.7.11-1, > >> the stdout > > from > >> msbuild.exe appears on the console where I invoke msbuild.sh as > expected. > >> But after a recent upgrade to 1.7.15-1, the stdout stops appearing. > >> By inspecting the running processes in the windows task manager, I > >> see that msbuild.exe is launching the compiler, etc. Notably, if I > >> replace the invocation of msbuild.exe with another program (e.g., > >> dir), I do see the expected stdout. > >> Further, if I execute the relevant commands in the native cmd shell, > >> I do > > see > >> the msbuild.exe output. I considered tracking down the specific > >> package that lead to this regression, but I didn't find a mirror with > >> the older > > packages. > >> Below I've pasted the output of cygcheck -c for the working and > >> failing systems. Can somebody advise me on a sensible next steps to > >> recovering the stdout of msbuild.exe? > >> > >> Please CC me in responses. > >> > >> Thanks, > >> Brian > > > > <snip> > > > > Try both of the following: > > > > 1. Update to latest development snapshot, should resolve the bug you > > are primarily observing. > > 2. Set the CYGWIN environment variable to pipe_byte. Cygwin now uses > > message pipes by default, which are not compatible with .NET Framework > > and Visual C++ runtimes (not currently documented anywhere in Cygwin > > or MS documentation). > > For kicks, I tried 2 by itself. This didn't change the behavior. > Next, I tried 1 by itself as described in [1]. This worked. Adding in > CYGWIN=pipe_byte did not cause anything to change. So I presume this will > be fixed in the next release. Thanks for your time.
That's because "pipe_byte" won't fix the problem of a hang. What pipe_byte will fix is allow all non-Cygwin programs to properly handle reading from standard input. That's because unmanaged VC++ and managed .NET runtimes dont support reading a message pipe standard input. This compatibility issue with these common Microsoft runtimes isn't yet in the Cygwin documentation as far as I know, which is why I'm pointing it out to you - since you're obviously using non-Cygwin programs. Read the past discussions about this issue and you'll see why it's necessary, if you want the technical details. A message pipe might seem to work 99% of the time, but then break. -- 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
