On Darwin, pass CMAKE_OSX_ARCHITECTURES with just the host during the CMake portion of the bootstrap. This makes bootstrapping immune to whatever defaults are set in swift-llbuild's own CMake files.

abertelrud · abertelrud · commit 5a8b584d06a5 · 2020-09-08T12:35:55.000-07:00
diff --git a/Utilities/bootstrap b/Utilities/bootstrap
@@ -464,6 +464,10 @@ def build_llbuild(args):
         "-DLLBUILD_SUPPORT_BINDINGS:=Swift",
     ]
 
+    # On Darwin, make sure we're building for the host architecture.
+    if platform.system() == 'Darwin':
+        flags.append("-DCMAKE_OSX_ARCHITECTURES:=%s" % (get_build_target(args).split('-')[0]))
+
     if args.sysroot:
         flags.append("-DSQLite3_INCLUDE_DIR=%s/usr/include" % args.sysroot)
 

Original file line number	Diff line number	Diff line change
`@@ -464,6 +464,10 @@ def build_llbuild(args):`
`464`	`464`	`"-DLLBUILD_SUPPORT_BINDINGS:=Swift",`
`465`	`465`	`]`
`466`	`466`
	`467`	`+ # On Darwin, make sure we're building for the host architecture.`
	`468`	`+ if platform.system() == 'Darwin':`
	`469`	`+ flags.append("-DCMAKE_OSX_ARCHITECTURES:=%s" % (get_build_target(args).split('-')[0]))`
	`470`	`+`
`467`	`471`	`if args.sysroot:`
`468`	`472`	`flags.append("-DSQLite3_INCLUDE_DIR=%s/usr/include" % args.sysroot)`
`469`	`473`