Its not enough to just serialize the clean step...
diff --git a/Makefile b/Makefile
index 674b83a..8820ca0 100644
--- a/Makefile
+++ b/Makefile
@@ -1651,7 +1651,7 @@
endif
endif
$(Q)$(MAKE) -j 1 -C third_party/openssl clean
- $(Q)(unset CPPFLAGS; $(MAKE) -C third_party/openssl build_crypto build_ssl)
+ $(Q)(unset CPPFLAGS; $(MAKE) -j 1 -C third_party/openssl build_crypto build_ssl)
$(Q)mkdir -p $(LIBDIR)/$(CONFIG)/openssl
$(Q)cp third_party/openssl/libssl.a third_party/openssl/libcrypto.a $(LIBDIR)/$(CONFIG)/openssl
diff --git a/templates/Makefile.template b/templates/Makefile.template
index 0af3dbd..797f0ab 100644
--- a/templates/Makefile.template
+++ b/templates/Makefile.template
@@ -860,7 +860,7 @@
endif
endif
$(Q)$(MAKE) -j 1 -C third_party/openssl clean
- $(Q)(unset CPPFLAGS; $(MAKE) -C third_party/openssl build_crypto build_ssl)
+ $(Q)(unset CPPFLAGS; $(MAKE) -j 1 -C third_party/openssl build_crypto build_ssl)
$(Q)mkdir -p $(LIBDIR)/$(CONFIG)/openssl
$(Q)cp third_party/openssl/libssl.a third_party/openssl/libcrypto.a $(LIBDIR)/$(CONFIG)/openssl
