diff --git a/main.go b/main.go
index 0739854..e814c56 100644
--- a/main.go
+++ b/main.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"embed"
+	"fmt"
 	"io"
 	"log"
 	"os"
@@ -16,50 +17,79 @@ var alpineKeys embed.FS
 func main() {
 	config, err := readConfig()
 	must(err)
+	must(run(config, "rootfs/", "cache/"))
 
-	must(os.RemoveAll("rootfs/"))
+}
 
-	must(os.MkdirAll("rootfs/etc/apk/keys", 0700))
-	must(os.WriteFile("rootfs/etc/apk/repositories", []byte(
-		`https://dl-cdn.alpinelinux.org/alpine/v3.17/main
-https://dl-cdn.alpinelinux.org/alpine/v3.17/community`), 0600))
-	must(os.WriteFile("rootfs/etc/resolv.conf", []byte(
-		`nameserver 8.8.8.8`), 0644))
-	keys, err := alpineKeys.ReadDir("alpine/keys")
-	must(err)
-	for _, entry := range keys {
-		o, err := os.Create(path.Join("rootfs/etc/apk/keys/", entry.Name()))
-		must(err)
-		s, err := alpineKeys.Open(path.Join("alpine/keys", entry.Name()))
-		must(err)
-		_, err = io.Copy(o, s)
-		must(err)
+func run(config Config, rootfs string, cache string) (err error) {
+	if err = os.RemoveAll("rootfs/"); err != nil {
+		return
 	}
 
-	must(os.MkdirAll("cache/_var_cache_apk", 0700))
+	if err = os.MkdirAll("rootfs/etc/apk/keys", 0700); err != nil {
+		return
+	}
+	if err = os.WriteFile("rootfs/etc/apk/repositories", []byte(
+		`https://dl-cdn.alpinelinux.org/alpine/v3.17/main
+https://dl-cdn.alpinelinux.org/alpine/v3.17/community`), 0600); err != nil {
+		return
+	}
+
+	if err = os.WriteFile("rootfs/etc/resolv.conf", []byte(`nameserver 8.8.8.8`), 0644); err != nil {
+		return
+	}
+	keys, err := alpineKeys.ReadDir("alpine/keys")
+	if err != nil {
+		return
+	}
+	for _, entry := range keys {
+		o, err := os.Create(path.Join("rootfs/etc/apk/keys/", entry.Name()))
+		if err != nil {
+			return err
+		}
+		s, err := alpineKeys.Open(path.Join("alpine/keys", entry.Name()))
+		if err != nil {
+			return err
+		}
+		if _, err = io.Copy(o, s); err != nil {
+			return err
+		}
+	}
+
+	if err = os.MkdirAll("cache/_var_cache_apk", 0700); err != nil {
+		return
+	}
 	os.Remove("rootfs/etc/apk/cache")
-	must(os.Symlink("/var/cache/apk", "rootfs/etc/apk/cache"))
+	if err = os.Symlink("/var/cache/apk", "rootfs/etc/apk/cache"); err != nil {
+		return
+	}
 	// must(os.MkdirAll("rootfs/var/cache", 0700))
 	// must(os.RemoveAll("rootfs/var/cache/apk"))
 	// must(os.Symlink("../../../cache/apk", "rootfs/var/cache/apk"))
+	// must(os.Remove("rootfs/var/cache/apk"))
 	cmd := exec.Command("apk", "add",
 		"--root", "rootfs",
 		"--initdb",
 		"--cache-dir", "../cache/_var_cache_apk",
 		"apk-tools")
-	must(cmd.Run(), "apk add apk-tools")
-	// must(os.Remove("rootfs/var/cache/apk"))
+	if err = cmd.Run(); err != nil {
+		return fmt.Errorf("apk add apk-tools: %w", err)
+	}
 
 	cached := append(config.Cache, "/var/cache/apk")
 	var cachedParams []string
 	for _, c := range cached {
 		cacheDir := path.Join("./cache", strings.ReplaceAll(c, "/", "_"))
-		must(os.MkdirAll(cacheDir, 0700))
+		if err = os.MkdirAll(cacheDir, 0700); err != nil {
+			return
+		}
 		cachedParams = append(cachedParams, "--bind", cacheDir, c)
 	}
 
 	tmp, err := os.MkdirTemp("", "repro-run-")
-	must(err)
+	if err != nil {
+		return
+	}
 	defer os.RemoveAll(tmp)
 	log.Println("/work = " + tmp)
 
@@ -78,20 +108,25 @@ https://dl-cdn.alpinelinux.org/alpine/v3.17/community`), 0600))
 
 	cmd = exec.Command("bwrap", append(params,
 		"apk", "add", "busybox", "busybox-suid", "libc-utils", "alpine-baselayout", "alpine-conf", "alpine-release")...)
-	// cmd.Stdout = os.Stdout
-	// cmd.Stderr = os.Stderr
-	must(cmd.Run(), "bwrap apk add")
+	if err = cmd.Run(); err != nil {
+		return fmt.Errorf("bwrap apk add: %w", err)
+	}
 	cmd = exec.Command("bwrap", append(params,
 		"--uid", "0",
 		"adduser", "-u", "1000", "-D", "repro")...)
-	must(cmd.Run(), "bwrap adduser repro")
+	if err = cmd.Run(); err != nil {
+		return fmt.Errorf("bwrap adduser repro: %w", err)
+	}
 
 	cmd = exec.Command("bwrap", append(params, strings.Split(config.Command, " ")...)...)
 	cmd.Stdout = os.Stdout
 	cmd.Stdin = os.Stdin
 	cmd.Stderr = os.Stderr
-	must(cmd.Run())
+	if err = cmd.Run(); err != nil {
+		return fmt.Errorf("running Command: %w", err)
+	}
 
+	return
 }
 
 func must(err error, where ...string) {