calling system gives exception, waitForProcess

Neil Mitchell ndmitchell at
Mon Nov 28 18:16:25 EST 2005


On Windows XP, with GHC 6.4.1, I get the following error consistently
when calling "system", from the module System. I get this error on two
entirely different computers, one slow (750Mhz) system, and one fast
(3Ghz) system.

Its easiest to demonstrate when using GHCi, but the problem also
occurs when running Haskell programs compiled with GHC.

Prelude System> system "yhi Main"
PreludeList.!!: on empty list
*** Exception: waitForProcess: does not exist (No such file or directory)

>From a windows standard console, in the same current directory, I get:
Windows> yhi Main
PreludeList.!!: on empty list

When calling yhi using system in other circumstances (on other
programs), it works fine. The "PreludeList.!! ..." text is being
generated by the yhi program.

The yhi program is written in C, and is available from Unfortunately this is probably a
bit too large to use as a minimal test case, and takes quite a while
to install/configure at the moment.

Any idea why the waitForProcess error is being raised?



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