A couple makefiles had misspelled the magic .PHONY target as PHONY.
$(pg_isolation_regress_installcheck) \
$(ISOLATIONCHECKS)
-PHONY: submake-test_decoding submake-regress check \
+.PHONY: submake-test_decoding submake-regress check \
regresscheck regresscheck-install-force \
isolationcheck isolationcheck-install-force
--outputdir=./isolation_output \
$(ISOLATIONCHECKS)
-PHONY: check isolation-check
+.PHONY: check isolation-check
submake-isolation:
$(MAKE) -C $(top_builddir)/src/test/isolation all