nix: fix Nix shell (abiosoft#436)

Makefile

@@ -21,7 +21,7 @@ BIN_NAME := colima
 LDFLAGS := $(VERSION_VARIABLES)
 
 .PHONY: all
-all: build 
+all: build
 
 .PHONY: clean
 clean:
@@ -60,6 +60,10 @@ install:
 lint: ## Assumes that golangci-lint is installed and in the path.  To install: https://golangci-lint.run/usage/install/
 	golangci-lint --timeout 3m run
 
+.PHONY: print-binary-name
+print-binary-name:
+	@echo $(OUTPUT_DIR)/$(OUTPUT_BIN)
+
 .PHONY: nix-derivation-shell
 nix-derivation-shell:
 	$(eval DERIVATION=$(shell nix-build))

colima.nix

@@ -2,12 +2,15 @@
 
 with pkgs;
 
-buildGo118Module {
+buildGoModule {
   name = "colima";
   pname = "colima";
   src = ./.;
   nativeBuildInputs = [ installShellFiles makeWrapper git ];
-  vendorSha256 = "sha256-jDzDwK7qA9lKP8CfkKzfooPDrHuHI4OpiLXmX9vOpOg=";
+  vendorSha256 = "sha256-tsMQMWEkTE1NhevcqBETGWiboqL6QTepgnIo4B5Y4wQ=";
+  CGO_ENABLED = 1;
+
+  subPackages = [ "cmd/colima" ];
 
   # `nix-build` has .git folder but `nix build` does not, this caters for both cases
   preConfigure = ''

shell.nix

@@ -10,6 +10,17 @@ pkgs.mkShell {
   ];
   shellHook = ''
     echo Nix Shell with $(go version)
-    alias colima="$PWD/_output/binaries/colima-Darwin-arm64"
+    echo
+
+    COLIMA_BIN="$PWD/$(make print-binary-name)"
+    if [ ! -f "$COLIMA_BIN" ]; then
+        echo "Run 'make' to build Colima."
+        echo
+    fi
+
+    set -x
+    set -x
+    alias colima="$COLIMA_BIN"
+    set +x
   '';
 }