SGI seemingly does not have unsetenv(). FIXME: how to unset

environment variables on SGI without tweaking environ yourself.

configure.ac

 # Process this file with autoconf to produce a configure script.
 
 AC_PREREQ(2.52)
-AC_INIT([albert], [1.2-pre1], [dani@mathematik.uni-freiburg.de])
+AC_INIT([albert], [1.2-pre2], [dani@mathematik.uni-freiburg.de])
 
 AC_CONFIG_SRCDIR([ALBERT/src/Common/albert.h])
 AM_MAINTAINER_MODE
@@ -64,7 +64,7 @@ AC_PREFIX_DEFAULT([`pwd`])
 AC_CHECK_LIB([m],[main],,
              [AC_MSG_ERROR([no math library, exiting...!])] )
 
-AC_CHECK_FUNCS([alarm pow sqrt strdup strchr strstr],,
+AC_CHECK_FUNCS([alarm pow sqrt strdup strchr strstr unsetenv],,
 	       [AC_MSG_ERROR([Sorry, these are needed..])])
 
 AC_FUNC_MALLOC