hardcode cargo

Makefile

@@ -4,16 +4,15 @@
 VARS ?= vars.mk
 -include $(VARS)
 
-CARGO ?= $(shell which cargo)
 override CARGO_BUILD_ARGS += --features "$(FEATURES)" --color=always
 
 all: build
 
 run: build
-	$(CARGO) run $(CARGO_BUILD_ARGS)
+	cargo run $(CARGO_BUILD_ARGS)
 
 build:
-	$(CARGO) build $(CARGO_BUILD_ARGS)
+	cargo build $(CARGO_BUILD_ARGS)
 
 release: override CARGO_BUILD_ARGS += --release
 release: build
@@ -23,21 +22,21 @@ doc:
 
 test-release: override CARGO_BUILD_ARGS += --release
 test-release:
-	$(CARGO) test $(TEST) $(CARGO_BUILD_ARGS) -- --nocapture
+	cargo test $(TEST) $(CARGO_BUILD_ARGS) -- --nocapture
 
 test:
-	$(CARGO) test $(TEST) $(CARGO_BUILD_ARGS) -- --nocapture
+	cargo test $(TEST) $(CARGO_BUILD_ARGS) -- --nocapture
 
 test-panic: override FEATURES += panic-on-error
 test-panic:
 	RUST_BACKTRACE=1 \
-		$(CARGO) test \
+		cargo test \
 			$(TEST) \
 			$(CARGO_BUILD_ARGS) -- \
 			--nocapture
 
 test-st:
-	$(CARGO) test $(TEST) $(CARGO_BUILD_ARGS) -- --nocapture --test-threads 1
+	cargo test $(TEST) $(CARGO_BUILD_ARGS) -- --nocapture --test-threads 1
 
 clean:
 	rm -rf target/