Add Makefile and fix pacman.go

Makefile

@@ -0,0 +1,25 @@
+.PHONY: fmt vet check githook
+
+STAGED_GO := $(shell git diff --cached --name-only --diff-filter=ACM | grep '\.go$$')
+STAGED_PKGS := $(shell echo "$(STAGED_GO)" | tr ' ' '\n' | xargs -I{} dirname {} | sort -u | sed 's|^|./|')
+
+fmt:
+	@if [ -z "$(STAGED_GO)" ]; then exit 0; fi; \
+	unformatted=$$(gofmt -l $(STAGED_GO)); \
+	if [ -n "$$unformatted" ]; then \
+		echo "$$unformatted: unformatted staged file"; \
+		exit 1; \
+	fi
+
+vet:
+	@if [ -z "$(STAGED_GO)" ]; then exit 0; fi; \
+	go vet $(STAGED_PKGS)
+
+check: fmt vet
+
+githook:
+	@mkdir -p .git/hooks
+	@echo '#!/bin/sh' > .git/hooks/pre-commit
+	@echo 'make check' >> .git/hooks/pre-commit
+	@chmod +x .git/hooks/pre-commit
+	@echo "Installed pre-commit hook: .git/hooks/pre-commit"

pkg/pacman/pacman.go

@@ -172,7 +172,7 @@ func InstallAUR(f *fetch.Fetcher, pkgName string) error {
 	cloneCmd.Stdout = io.MultiWriter(os.Stdout, state.GetLogWriter())
 	cloneCmd.Stderr = io.MultiWriter(os.Stderr, state.GetLogWriter())
 	if err := cloneCmd.Run(); err != nil {
-		errMsg := fmt.Sprintf("failed to clone AUR repo: %w\n", err)
+		errMsg := fmt.Sprintf("failed to clone AUR repo: %v\n", err)
 		state.Write([]byte("error: " + errMsg))
 		return fmt.Errorf("failed to clone AUR repo: %w", err)
 	}
@@ -184,7 +184,7 @@ func InstallAUR(f *fetch.Fetcher, pkgName string) error {
 	makepkgCmd.Stderr = io.MultiWriter(os.Stderr, state.GetLogWriter())
 	makepkgCmd.Dir = tmpDir
 	if err := makepkgCmd.Run(); err != nil {
-		errMsg := fmt.Sprintf("makepkg failed to build AUR package: %w\n", err)
+		errMsg := fmt.Sprintf("makepkg failed to build AUR package: %v\n", err)
 		state.Write([]byte("error: " + errMsg))
 		return fmt.Errorf("makepkg failed to build AUR package: %w", err)
 	}