Meanwhile, can you additionally test the attached program, which doesn't use NSProcessInfo (upstream has some suspicions that's the class where the bug is)? You can reuse the same GNUmakefile I sent you earlier.
#import <Foundation/Foundation.h>
int
main (void)
{
CREATE_AUTORELEASE_POOL (pool);
NSString *foo = @"Test\n";
printf ("%s", [foo cString]);
RELEASE (pool);
exit (EXIT_SUCCESS);
}

