make with --no-builtin-variables

ParadoxV5 · kddnewton · commit 98d7192dcce6 · 2025-09-13T13:29:19.000-04:00
As observed in #2771, `?=` thinks that implicit definitions of CC`, `AR` and `ARFLAGS` are explicit. Disabling implicit variables is more straightforward than adapting the `Makefile` and `extconf.rb` around them.
diff --git a/ext/prism/extconf.rb b/ext/prism/extconf.rb
@@ -51,6 +51,7 @@ def make(env, target)
     system(
       env,
       RUBY_PLATFORM.match?(/openbsd|freebsd/) ? "gmake" : "make",
+      "--no-builtin-variables", # don't let GNU make implicit variables override variable fallbacks in the Makefile
       target,
       exception: true
     )

Original file line number	Diff line number	Diff line change
`@@ -51,6 +51,7 @@ def make(env, target)`
`51`	`51`	`system(`
`52`	`52`	`env,`
`53`	`53`	`RUBY_PLATFORM.match?(/openbsd\|freebsd/) ? "gmake" : "make",`
	`54`	`+ "--no-builtin-variables", # don't let GNU make implicit variables override variable fallbacks in the Makefile`
`54`	`55`	`target,`
`55`	`56`	`exception: true`
`56`	`57`	`)`