diff -up firefox-154.0-build/firefox-154.0/config/rules.mk.pgo-simple firefox-154.0-build/firefox-154.0/config/rules.mk
--- firefox-154.0-build/firefox-154.0/config/rules.mk.pgo-simple	2026-08-12 23:13:24.000000000 +0200
+++ firefox-154.0-build/firefox-154.0/config/rules.mk	2026-08-13 12:37:48.663956455 +0200
@@ -172,9 +172,14 @@ endif
 # Don't build SIMPLE_PROGRAMS during the MOZ_PROFILE_GENERATE pass, and do not
 # attempt to install them
 ifdef MOZ_PROFILE_GENERATE
+_PGO_SKIPPED_SIMPLE_PROGRAMS := $(SIMPLE_PROGRAMS)
 $(foreach category,$(INSTALL_TARGETS),\
   $(eval $(category)_FILES := $(foreach file,$($(category)_FILES),$(if $(filter $(SIMPLE_PROGRAMS),$(notdir $(file))),,$(file)))))
 SIMPLE_PROGRAMS :=
+# Create empty placeholders so misc:: install rules from backend.mk
+# that copy these binaries to _tests/ don't fail on missing files.
+$(_PGO_SKIPPED_SIMPLE_PROGRAMS):
+	@touch $@
 endif
 
 ifdef COMPILE_ENVIRONMENT