From 984752b81247459f7c83b0a7182de4e65c9a746b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Motiejus=20Jak=C5=A1tys?= <motiejus@jakstys.lt>
Date: Wed, 25 Aug 2021 08:53:03 +0300
Subject: [PATCH] remove unused archs

I am not using nor need arm64 and windows. Removing these from the
Makefile. If you see this message and feel like they should be added
back (or different archs), ping me.
---
 Makefile  | 17 +++++++----------
 README.md | 14 ++++++++++++++
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/Makefile b/Makefile
index 89e2120..ba8c5ca 100644
--- a/Makefile
+++ b/Makefile
@@ -1,30 +1,27 @@
 SCRIPTS = $(shell awk '/#!\/bin\/(ba)?sh/&&FNR==1{print FILENAME}' $(shell git ls-files))
 GODEPS = $(shell git ls-files '*.go' go.mod go.sum)
 GOBIN = $(shell go env GOPATH)/bin/
-
-GOOSARCHS = $(sort \
-			darwin/amd64 \
-			darwin/arm64 \
-			linux/amd64 \
-			linux/arm64 \
-			windows/amd64/.exe)
+GOOSARCHS = $(sort darwin/amd64 linux/amd64)
 
 VSN ?= $(shell git describe --dirty)
 VSNHASH = $(shell git rev-parse --verify HEAD)
 LDFLAGS = -ldflags "-X main.Version=$(VSN) -X main.VersionHash=$(VSNHASH)"
 
+undocker: ## builds binary for the current architecture
+	CGO_ENABLED=0 go build $(LDFLAGS) -o $@
+
 .PHONY: test
 test:
 	go test -race -cover ./...
 
 define undockertarget
-UNDOCKERS += undocker-$(1)-$(2)-$(VSN)$(firstword $(3))
-undocker-$(1)-$(2)-$(VSN)$(firstword $(3)): $(GODEPS)
+UNDOCKERS += undocker-$(1)-$(2)-$(VSN)
+undocker-$(1)-$(2)-$(VSN): $(GODEPS)
 	CGO_ENABLED=0 GOOS=$(1) GOARCH=$(2) go build $(LDFLAGS) -o $$@
 endef
 
 $(foreach goosarch,$(GOOSARCHS),\
-	$(eval $(call undockertarget,$(word 1,$(subst /, ,$(goosarch))),$(word 2,$(subst /, ,$(goosarch))),$(word 3,$(subst /, ,$(goosarch))))))
+	$(eval $(call undockertarget,$(word 1,$(subst /, ,$(goosarch))),$(word 2,$(subst /, ,$(goosarch))))))
 
 .PHONY: all
 all: $(UNDOCKERS)
diff --git a/README.md b/README.md
index 142715d..4a6b899 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,19 @@ systemd, FreeBSD Jails, and many others.
 
 Undocker has no dependencies outside Golang stdlib.
 
+Installation
+------------
+
+We recommend using [officially released binaries][3]. To build the project
+instead, run:
+
+```
+$ make undocker
+```
+
+The number of officially released binaries is quite limited. If you'd like me
+to expand a list, please contribute a patch to the Makefile.
+
 Usage: convert docker image to rootfs
 -------------------------------------
 
@@ -107,3 +120,4 @@ MIT
 
 [1]: https://www.freedesktop.org/software/systemd/man/systemd.exec.html
 [2]: https://fly.io/blog/docker-without-docker/
+[3]: http://git.sr.ht/~motiejus/undocker