Singular

Once again after a routine update of cygwin, Singular is no longer working. Typing "Singular" at the cygwin prompt gives the all-too-familiar "Segment fault/Bus error" message.

However, first giving command

export PATH=/usr/local/bin:/usr/bin:/bin

DOES allow Singular to work (and, if I also start X, ESingular) from within cygwin.

In the past this problem has been traced to difficulties with the Windows path variable having some illegal character, but I don't see any in it (although I don't know how to examine it in such a way that illegal characters aren't automatically suppressed!). My path includes:

v:cygwinusrlocalbin;v:cygwinusrbin;v:cygwinbin;v:cygwinusrx11r6bin;v:cygwinlibsingular;

The various Singular-specific environment variables in Windows include

SINGULAR_BIN_DIR=/usr/lib/Singular
SINGULAR_ROOT_DIR=/usr/share/Singular

as specified at viewtopic.php?p=1557#1557.

I do not understand why this problem arises anew each time Singular gets updated by cygwin.

This problem arises if the path variable is too long. Please insert the following line in the scripts "binSingular" and "binESingular" before line 9:



And add further path entries you need while running Singular.

If you need to use a very long path inside Singular please contact me again and I will provide you an executable without this limitation. (The limitation is at the moment around 1200 characters.)

Future versions of Singular may not be affected by this behaviour. Please refer to the next change log for details. (Current Version: 3.0.2)

Yes, I can now start Singular or ESingular after first starting Cygwin. Also without first starting Cygwin manually but by running the shortcuts "Singular (Emacs and X-Server) (experimental)", "Singular (rxvt)", and "Singular (Terminal)". Also by running first the shortcut "Start X - Server (needed for emacs and surf)" and then the shortcut "Singular (Emacs)".

I did not add any path entries beyond the three you explicitly listed. What other additions might be needed?

I cannot think of any more useful path entries for Singular, except maybeif you want to call scripts / applications from the local directory within Singular.

Sincerely,

Oliver Wienand
Singular Team