Makefile.am:
TESTS += test-btowc1.sh test-btowc2.sh
-TESTS_ENVIRONMENT += EXEEXT='@EXEEXT@' LOCALE_FR='@LOCALE_FR@' LOCALE_FR_UTF8='@LOCALE_FR_UTF8@'
+TESTS_ENVIRONMENT += LOCALE_FR='@LOCALE_FR@' LOCALE_FR_UTF8='@LOCALE_FR_UTF8@'
check_PROGRAMS += test-btowc