The testsuite is distributed, so distclean must not delete it.
Thanks to Harry Thijssen <pspp4windows@gmail.com> for reporting the problem.
tests/perl-module.at
TESTSUITE = $(srcdir)/tests/testsuite
-DISTCLEANFILES += tests/atconfig tests/atlocal $(TESTSUITE)
+DISTCLEANFILES += tests/atconfig tests/atlocal
AUTOTEST_PATH = tests/data:tests/language/lexer:tests/libpspp:tests/output:src/ui/terminal:utilities
$(srcdir)/tests/testsuite.at: tests/testsuite.in tests/automake.mk