'cmd /C start cmd' no longer non-blocking (base-cygwin 3.1-1), but used to work (in base-cygwin 3.0-1)

Petrisor Eddy-Marian-B36037 B36037@freescale.com
Fri May 4 13:46:00 GMT 2012


I am using at work cygwin on various machines (XP and Windows 7) and made several scripts that use gnu utilities from cygwin. One of those is a script that starts in paralel instances of cmd various parts of a build system through a sh script that invokes 'cmd /C start ...' to start those parts of the build system in a non-blocking fashion.

Recently, on one of the machines which had its cygwin installation upgraded, I have observed that the cmd instances do not start in a non-blocking fashion anymore, but instead wait for the process to finish.

To be more precise, following the following steps should lead to two interactive windows, one with the sh prompt and one with the cmd prompt, both waiting for user input:
1 - start a cygwin (or sh) command window
2 - type "cmd /C start cmd"

Expected result:
Two interactive and usable windows, one with the sh prompt, one with the cmd prompt, both waiting for user input.

Actual result:
Two windows, one with sh and one with cmd, Cygwin/sh window blocked and waiting for the cmd window to finish.

On another machine that hasn't had its cygwin install upgraded, the behaviour is the expected one. Here are the versions of the relevant packages that are found by the setup.exe to be upgradable on the working machine and the versions of the same packages on the non-working machine:

Working machine package versions:
base-cygwin 3.0-1
csih 0.9.5-1
cygutils 1.4.8-1
cygwin 1.7.11-1
rebase 4.0.1-1

Non-working machine package versions:
base-cygwin 3.1-1
csih 0.9.6-1
cygutils 1.4.10-2
cygwin 1.7.14-2
rebase 4.1.0-1

Note: There are other packages which could be upgraded on the working machine, but they are irrelevant: diffutils, file, gawk, groff sed and tzcode.

Any help would be appreciated.

P.S.: Please CC me, I am not subscribed.


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