How to make Cygwin the default shell for Jenkins? - build

Question

I'm trying to come up with some sensible solution for a build written using SCons, which relies on quite a lot of applications to be accessible in a Unix-like way, using Unix-like paths etc. However, when I'm trying to use SCons plugin, or Git plugin in Jenkins, it tries to invoke the plugins using something like cmd /c git.exe - and this will certainly fail, because Git was installed using Cygwin and is only known in Cygwin shell, but not in CMD. But even if I could make git and the rest available to cmd.exe, other problems arise: the Cygwin version of Git expects paths to have forward slashes and treats backward slashes as escape characters. Idiotic Windows file-system related issues kick in too (I can't give Jenkins permissions to delete my own files!).
So, is there a way to somehow make Jenkins only use Cygwin shell, and never cmd.exe? Or should I be prepared to run some Linux in a VM to have this handled?

Answer 1

You could configure Jenkins to execute the cygwin command with the specific shell command, as follows:
c:\cygwin\bin\mintty --hold always --exec /cygdrive/c/path/to/bash/script.sh
Where script.sh will execute all the commands needed for the Jenkins execution.

Answer 2

Just for the record here's what I ended up doing:
Added a user SYSTEM to Cygwin, mkpasswd -u SYSTEM
Edited /etc/passwd by adding the newly created user's home directory to the record. Now it looks something like the below:
SYSTEM:*:18:544:,S-1-5-18:/home/SYSTEM:
Copied my own user's configuration settings such as .netrc, .ssh and so on into the SYSTEM home. Then, from Windows Explorer, through an array of popups I've claimed ownership of all of these files to SYSTEM user. One by one! I love Microsoft!
In Jenkins I now run a wrapper for my build that sets some other environment variables etc. by calling c:\cygwin\bin\bash --login -i /path/to/script/script
Gave it up because of other difficulties in configuration and made Jenkins service run under my user rather then SYSTEM. Here's a blog post on how to do it: http://antagonisticpleiotropy.blogspot.co.il/2012/08/running-jenkins-in-windows-with-regular.html but, basically, you need to open Windows services, then find Jenkins service, select it's properties, go to "Logon" tab and change the user to the "this user".

Answer 3

One way to do this is to start your "execute shell" build steps with
#!c:\cygwin\bin\bash --login
The trick is of course that it resets your current directory so you need to
cd `cygpath $WORKSPACE`
to get back to the workspace.

Answer 4

Adding to thon56's good answer: this is helpful: "set -ex"
#!c:\cygwin\bin\bash --login
cd `cygpath $WORKSPACE`
set -ex
Details:
-e to exit on error. This is important if you want your jobs to fail on error.
-x to echo command to the screen, if desired.
You can also use #!c:\cygwin\bin\bash --login -ex, but that echos a lot of login steps that you most likely don't care to see.