commit f66ea739a938bb3b4eec0bf53006e05420487b79
Author:     Jacob Welsh <jfw>
AuthorDate: Thu Sep 28 15:29:51 2023 +0000
Commit:     Jacob Welsh <jfw>
CommitDate: Thu Sep 28 15:29:51 2023 +0000

    fix parallel build from top-level Makefile
    
    When $(MAKE) is expanded from another variable, it breaks some required magic and make complains with "warning: jobserver unavailable: using -j1.  Add '+' to parent make rule."
    
    Rather than adding even more obscure magic and prefixing the recipes with +, just expand them out since there's not that many subdirs.
    
    Still suboptimal, in that the sub-makes are still forced to complete sequentially (one subdir before the other). I'm not as yet seeing a tidy solution here, without exploding even more phony targets.

diff --git a/Makefile b/Makefile
index 314edad444..c4a9040c53 100644
--- a/Makefile
+++ b/Makefile
@@ -1,13 +1,15 @@
-MAKE_SUBDIRS = $(MAKE) -C src $@ && $(MAKE) -C doc $@
-
 all:
-	$(MAKE_SUBDIRS)
+	$(MAKE) -C src all
+	$(MAKE) -C doc all
 
 check:
-	$(MAKE_SUBDIRS)
+	$(MAKE) -C src check
+	$(MAKE) -C doc check
 
 install:
-	$(MAKE_SUBDIRS)
+	$(MAKE) -C src install
+	$(MAKE) -C doc install
 
 clean:
-	$(MAKE_SUBDIRS)
+	$(MAKE) -C src clean
+	$(MAKE) -C doc clean