Merge pull request #4380 from rata/makefile-no-envs

Makefile: Don't read COMMIT, BUILDTAGS, EXTRA_BUILDTAGS from env vars

Author: AkihiroSuda

Makefile

@@ -14,10 +14,11 @@ GIT_BRANCH := $(shell git rev-parse --abbrev-ref HEAD 2>/dev/null)
 GIT_BRANCH_CLEAN := $(shell echo $(GIT_BRANCH) | sed -e "s/[^[:alnum:]]/-/g")
 RUNC_IMAGE := runc_dev$(if $(GIT_BRANCH_CLEAN),:$(GIT_BRANCH_CLEAN))
 PROJECT := github.com/opencontainers/runc
-BUILDTAGS ?= seccomp urfave_cli_no_docs
+EXTRA_BUILDTAGS :=
+BUILDTAGS := seccomp urfave_cli_no_docs
 BUILDTAGS += $(EXTRA_BUILDTAGS)
 
-COMMIT ?= $(shell git describe --dirty --long --always)
+COMMIT := $(shell git describe --dirty --long --always)
 EXTRA_VERSION :=
 VERSION := $(shell cat ./VERSION)$(EXTRA_VERSION)
 LDFLAGS_COMMON := -X main.gitCommit=$(COMMIT) -X main.version=$(VERSION)