diff --git a/tools/scripts/Makefile.arch b/tools/scripts/Makefile.arch
index eabfe9f411d9..ed5f008d400e 100644
--- a/tools/scripts/Makefile.arch
+++ b/tools/scripts/Makefile.arch
@@ -38,7 +38,13 @@ ifeq ($(ARCH),loongarch64)
        SRCARCH := loongarch
 endif
 
-LP64 := $(shell echo __LP64__ | ${CC} ${CFLAGS} -E -x c - | tail -n 1)
+# Probe for __LP64__ only when the compiler is installed: this runs at
+# parse time for every target, including ones that never compile, e.g.
+# install-build-deps, and would otherwise spew "gcc: not found" when the
+# compiler is not yet installed. Only the first word of CC is consulted,
+# as CC may carry arguments, e.g. 'ccache gcc'. When the guard fails it
+# prints nothing, leaving LP64 unset, as if the probe had failed.
+LP64 := $(shell if command -v $(firstword ${CC}) >/dev/null 2>&1; then echo __LP64__ | ${CC} ${CFLAGS} -E -x c -; fi | tail -n 1)
 ifeq ($(LP64), 1)
   IS_64_BIT := 1
 else
diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
index 46a3872b8762..378387f62960 100644
--- a/tools/scripts/Makefile.include
+++ b/tools/scripts/Makefile.include
@@ -98,7 +98,13 @@ else
   $(call allow-override,LLVM_STRIP,llvm-strip)
 endif
 
-CC_NO_CLANG := $(shell $(CC) -dM -E -x c /dev/null | grep -Fq "__clang__"; echo $$?)
+# The CC_NO_CLANG probe also runs at parse time for targets that never
+# compile, so guard it with 'command -v': when the compiler is not yet
+# installed, e.g. the first install-build-deps run, it would otherwise
+# spew "gcc: not found". Only the first word of CC is consulted, as CC
+# may carry arguments, e.g. 'ccache gcc'. A missing compiler leaves
+# CC_NO_CLANG at 1, as if the probe had failed.
+CC_NO_CLANG := $(shell if command -v $(firstword $(CC)) >/dev/null 2>&1; then $(CC) -dM -E -x c /dev/null; fi | grep -Fq "__clang__"; echo $$?)
 
 # Some tools require bpftool
 SYSTEM_BPFTOOL	?= bpftool