diff --git a/.gitignore b/.gitignore
index f0c64ac72..57f2db2a7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@
 _output/
 _build/
 bin/
+result
diff --git a/Makefile b/Makefile
index 92b795510..014e0867e 100644
--- a/Makefile
+++ b/Makefile
@@ -38,7 +38,7 @@ fmt:
 
 .PHONY: build
 build:
-	GOOS=$(GOOS) GOARCH=$(GOARCH) go build -ldflags="$(LDFLAGS)" -o $(OUTPUT_DIR)/$(OUTPUT_BIN) ./cmd/colima
+	GOOS=$(GOOS) GOARCH=$(GOARCH) CGO_ENABLED=0 go build -ldflags="$(LDFLAGS)" -o $(OUTPUT_DIR)/$(OUTPUT_BIN) ./cmd/colima
 	cd $(OUTPUT_DIR) && openssl sha256 -r -out $(OUTPUT_BIN).sha256sum $(OUTPUT_BIN)
 
 .PHONY: test
@@ -59,3 +59,9 @@ install:
 .PHONY: lint
 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: nix-derivation-shell
+nix-derivation-shell:
+	$(eval DERIVATION=$(shell nix-build))
+	echo $(DERIVATION) | grep ^/nix
+	nix-shell -p $(DERIVATION)
diff --git a/cmd/daemon/daemon.go b/cmd/daemon/daemon.go
index 66ad0be25..6255099d8 100644
--- a/cmd/daemon/daemon.go
+++ b/cmd/daemon/daemon.go
@@ -13,6 +13,7 @@ import (
 
 	"github.com/abiosoft/colima/cli"
 	"github.com/abiosoft/colima/daemon/process"
+	"github.com/abiosoft/colima/util/fsutil"
 	godaemon "github.com/sevlyar/go-daemon"
 	"github.com/sirupsen/logrus"
 )
@@ -22,7 +23,7 @@ var dir = process.Dir
 // daemonize creates the daemon and returns if this is a child process
 func daemonize() (ctx *godaemon.Context, child bool, err error) {
 	dir := dir()
-	if err := os.MkdirAll(dir, 0755); err != nil {
+	if err := fsutil.MkdirAll(dir, 0755); err != nil {
 		return nil, false, fmt.Errorf("cannot make dir: %w", err)
 	}
 
diff --git a/cmd/nerdctl.go b/cmd/nerdctl.go
index f3542ba00..9dc8c81bb 100644
--- a/cmd/nerdctl.go
+++ b/cmd/nerdctl.go
@@ -13,6 +13,8 @@ import (
 	"github.com/abiosoft/colima/cmd/root"
 	"github.com/abiosoft/colima/config"
 	"github.com/abiosoft/colima/environment/container/containerd"
+	"github.com/abiosoft/colima/util/fsutil"
+	"github.com/abiosoft/colima/util/osutil"
 	"github.com/spf13/cobra"
 )
 
@@ -96,7 +98,7 @@ var nerdctlLinkFunc = func() *cobra.Command {
 				ColimaApp string
 				Profile   string
 			}{
-				ColimaApp: os.Args[0],
+				ColimaApp: osutil.Executable(),
 				Profile:   config.CurrentProfile().ShortName,
 			}
 			var buf bytes.Buffer
@@ -112,7 +114,7 @@ var nerdctlLinkFunc = func() *cobra.Command {
 						return fmt.Errorf("error backing up existing file: %w", err)
 					}
 				}
-				if err := os.MkdirAll("/usr/local/bin", 0755); err != nil {
+				if err := fsutil.MkdirAll("/usr/local/bin", 0755); err != nil {
 					return nil
 				}
 				return os.WriteFile(nerdctlCmdArgs.path, buf.Bytes(), 0755)
diff --git a/config/dirs.go b/config/dirs.go
index 97a8d26f9..a85c20e7b 100644
--- a/config/dirs.go
+++ b/config/dirs.go
@@ -6,6 +6,9 @@ import (
 	"path/filepath"
 	"sync"
 
+	"github.com/abiosoft/colima/util/fsutil"
+	"github.com/abiosoft/colima/util/osutil"
+	"github.com/abiosoft/colima/util/shautil"
 	"github.com/sirupsen/logrus"
 )
 
@@ -28,7 +31,7 @@ func (r *requiredDir) Dir() string {
 	}
 
 	r.once.Do(func() {
-		if err := os.MkdirAll(dir, 0755); err != nil {
+		if err := fsutil.MkdirAll(dir, 0755); err != nil {
 			logrus.Fatal(fmt.Errorf("cannot make required directory: %w", err))
 		}
 	})
@@ -73,7 +76,9 @@ var (
 			if err != nil {
 				return "", err
 			}
-			return filepath.Join(dir, ".colima", "_wrapper"), nil
+			// generate unique directory for the current binary
+			uniqueDir := shautil.SHA1(osutil.Executable())
+			return filepath.Join(dir, ".colima", "_wrapper", uniqueDir.String()), nil
 		},
 	}
 )
diff --git a/daemon/daemon.go b/daemon/daemon.go
index d429a93c6..95c2ace2a 100644
--- a/daemon/daemon.go
+++ b/daemon/daemon.go
@@ -3,7 +3,6 @@ package daemon
 import (
 	"context"
 	"fmt"
-	"os"
 
 	"github.com/abiosoft/colima/cli"
 	"github.com/abiosoft/colima/config"
@@ -11,6 +10,8 @@ import (
 	"github.com/abiosoft/colima/daemon/process/gvproxy"
 	"github.com/abiosoft/colima/daemon/process/vmnet"
 	"github.com/abiosoft/colima/environment"
+	"github.com/abiosoft/colima/util/fsutil"
+	"github.com/abiosoft/colima/util/osutil"
 )
 
 // Manager handles running background processes.
@@ -55,14 +56,14 @@ func (l processManager) Dependencies(ctx context.Context) (deps process.Dependen
 
 func (l processManager) init() error {
 	// dependencies for network
-	if err := os.MkdirAll(process.Dir(), 0755); err != nil {
+	if err := fsutil.MkdirAll(process.Dir(), 0755); err != nil {
 		return fmt.Errorf("error preparing vmnet: %w", err)
 	}
 	return nil
 }
 
 func (l processManager) Running(ctx context.Context) (s Status, err error) {
-	err = l.host.RunQuiet(os.Args[0], "daemon", "status", config.CurrentProfile().ShortName)
+	err = l.host.RunQuiet(osutil.Executable(), "daemon", "status", config.CurrentProfile().ShortName)
 	if err != nil {
 		return
 	}
@@ -86,7 +87,7 @@ func (l processManager) Start(ctx context.Context) error {
 		return fmt.Errorf("error preparing network directory: %w", err)
 	}
 
-	args := []string{os.Args[0], "daemon", "start", config.CurrentProfile().ShortName}
+	args := []string{osutil.Executable(), "daemon", "start", config.CurrentProfile().ShortName}
 	opts := optsFromCtx(ctx)
 	if opts.Vmnet {
 		args = append(args, "--vmnet")
@@ -108,7 +109,7 @@ func (l processManager) Stop(ctx context.Context) error {
 	if s, err := l.Running(ctx); err != nil || !s.Running {
 		return nil
 	}
-	return l.host.RunQuiet(os.Args[0], "daemon", "stop", config.CurrentProfile().ShortName)
+	return l.host.RunQuiet(osutil.Executable(), "daemon", "stop", config.CurrentProfile().ShortName)
 }
 
 func optsFromCtx(ctx context.Context) struct {
diff --git a/daemon/process/gvproxy/deps.go b/daemon/process/gvproxy/deps.go
index d3fbce9f0..762fba0f5 100644
--- a/daemon/process/gvproxy/deps.go
+++ b/daemon/process/gvproxy/deps.go
@@ -10,6 +10,7 @@ import (
 	"github.com/abiosoft/colima/config"
 	"github.com/abiosoft/colima/daemon/process"
 	"github.com/abiosoft/colima/environment"
+	"github.com/abiosoft/colima/util/fsutil"
 )
 
 var _ process.Dependency = qemuBinsSymlinks{}
@@ -34,7 +35,7 @@ func (q qemuBinsSymlinks) Installed() bool {
 
 func (q qemuBinsSymlinks) Install(host environment.HostActions) error {
 	dir := q.dir()
-	if err := os.MkdirAll(dir, 0755); err != nil {
+	if err := fsutil.MkdirAll(dir, 0755); err != nil {
 		return fmt.Errorf("error preparing qemu wrapper bin directory: %w", err)
 	}
 	this, err := os.Executable()
@@ -69,7 +70,7 @@ func (q qemuShareDirSymlink) Installed() bool {
 func (q qemuShareDirSymlink) Install(host environment.HostActions) error {
 	dir := q.dir()
 	parent := filepath.Dir(dir)
-	if err := os.MkdirAll(parent, 0755); err != nil {
+	if err := fsutil.MkdirAll(parent, 0755); err != nil {
 		return fmt.Errorf("error preparing qemu wrapper shared directory: %w", err)
 	}
 
diff --git a/daemon/process/gvproxy/gvproxy.go b/daemon/process/gvproxy/gvproxy.go
index 0f3586694..ee7abd6ec 100644
--- a/daemon/process/gvproxy/gvproxy.go
+++ b/daemon/process/gvproxy/gvproxy.go
@@ -13,7 +13,7 @@ import (
 
 	"github.com/abiosoft/colima/cli"
 	"github.com/abiosoft/colima/daemon/process"
-	"github.com/abiosoft/colima/util"
+	"github.com/abiosoft/colima/util/shautil"
 	"github.com/containers/gvisor-tap-vsock/pkg/transport"
 	"github.com/containers/gvisor-tap-vsock/pkg/types"
 	"github.com/containers/gvisor-tap-vsock/pkg/virtualnetwork"
@@ -88,9 +88,9 @@ func MacAddress() string {
 	// there is not much concern about the precision of the uniqueness.
 	// this can be revisited
 	if macAddress == nil {
-		sum := util.SHA256Hash(process.Dir())
+		sum := shautil.SHA256(process.Dir())
 		macAddress = append(macAddress, baseHWAddr...)
-		macAddress = append(macAddress, sum[0:3]...)
+		macAddress = append(macAddress, sum.Bytes()[0:3]...)
 	}
 	return macAddress.String()
 }
diff --git a/default.nix b/default.nix
new file mode 100644
index 000000000..f9dc84cab
--- /dev/null
+++ b/default.nix
@@ -0,0 +1,34 @@
+let
+  pkgs = import <nixpkgs> { };
+in
+let
+  # override Lima to remove wrapper for qemu
+  # https://github.com/NixOS/nixpkgs/blob/f2537a505d45c31fe5d9c27ea9829b6f4c4e6ac5/pkgs/applications/virtualization/lima/default.nix#L35
+  lima = pkgs.lima.overrideAttrs (old: {
+    installPhase = ''
+      runHook preInstall
+      mkdir -p $out
+      cp -r _output/* $out
+      runHook postInstall
+    '';
+  });
+in
+pkgs.buildGo118Module rec {
+  name = "colima";
+  pname = "colima";
+  src = ./.;
+  nativeBuildInputs = with pkgs; [ installShellFiles makeWrapper git coreutils ];
+  vendorSha256 = "sha256-jDzDwK7qA9lKP8CfkKzfooPDrHuHI4OpiLXmX9vOpOg=";
+  preConfigure = ''
+    ldflags="-X github.com/abiosoft/colima/config.appVersion=$(git describe --tags --always)
+              -X github.com/abiosoft/colima/config.revision=$(git rev-parse HEAD)"
+  '';
+  postInstall = ''
+    wrapProgram $out/bin/colima \
+      --prefix PATH : ${pkgs.lib.makeBinPath [ pkgs.qemu lima ]}
+    installShellCompletion --cmd colima \
+      --bash <($out/bin/colima completion bash) \
+      --fish <($out/bin/colima completion fish) \
+      --zsh <($out/bin/colima completion zsh)
+  '';
+}
diff --git a/environment/vm/lima/lima.go b/environment/vm/lima/lima.go
index e29233cb9..8f05b0bdb 100644
--- a/environment/vm/lima/lima.go
+++ b/environment/vm/lima/lima.go
@@ -20,17 +20,21 @@ import (
 	"github.com/abiosoft/colima/config"
 	"github.com/abiosoft/colima/environment"
 	"github.com/abiosoft/colima/util"
+	"github.com/abiosoft/colima/util/osutil"
 	"github.com/abiosoft/colima/util/yamlutil"
 	"github.com/sirupsen/logrus"
 )
 
 // New creates a new virtual machine.
 func New(host environment.HostActions) environment.VM {
+	// environment variables for the subprocesses
 	var envs []string
 	envLimaInstance := limaInstanceEnvVar + "=" + config.CurrentProfile().ID
 	envSubprocess := config.SubprocessProfileEnvVar + "=" + config.CurrentProfile().ShortName
-	envs = append(envs, envLimaInstance, envSubprocess)
+	envBinary := osutil.EnvColimaBinary + "=" + osutil.Executable()
+	envs = append(envs, envLimaInstance, envSubprocess, envBinary)
 
+	// modify the PATH for qemu wrapper
 	binDir := filepath.Join(config.WrapperDir(), "bin")
 	envs = append(envs, "PATH="+util.AppendToPath(os.Getenv("PATH"), binDir))
 
diff --git a/environment/vm/lima/yaml_test.go b/environment/vm/lima/yaml_test.go
index 16d63dc65..e194f6b37 100644
--- a/environment/vm/lima/yaml_test.go
+++ b/environment/vm/lima/yaml_test.go
@@ -8,6 +8,7 @@ import (
 
 	"github.com/abiosoft/colima/config"
 	"github.com/abiosoft/colima/util"
+	"github.com/abiosoft/colima/util/fsutil"
 )
 
 func Test_checkOverlappingMounts(t *testing.T) {
@@ -43,6 +44,7 @@ func Test_checkOverlappingMounts(t *testing.T) {
 }
 
 func Test_config_Mounts(t *testing.T) {
+	fsutil.FS = fsutil.FakeFS
 	tests := []struct {
 		mounts        []string
 		isDefault     bool
diff --git a/shell.nix b/shell.nix
index dbd40bc2d..8e981e99c 100644
--- a/shell.nix
+++ b/shell.nix
@@ -6,8 +6,9 @@ pkgs.mkShell {
     go_1_18
     git
     coreutils
+    lima
   ];
   shellHook = ''
-    export CGO_ENABLED=0
+    echo Nix Shell with $(go version)
   '';
 }
diff --git a/util/downloader/download.go b/util/downloader/download.go
index bcc5dfdbe..8884034a9 100644
--- a/util/downloader/download.go
+++ b/util/downloader/download.go
@@ -7,7 +7,7 @@ import (
 
 	"github.com/abiosoft/colima/config"
 	"github.com/abiosoft/colima/environment"
-	"github.com/abiosoft/colima/util"
+	"github.com/abiosoft/colima/util/shautil"
 	"github.com/abiosoft/colima/util/terminal"
 )
 
@@ -37,7 +37,7 @@ type downloader struct {
 }
 
 func (d downloader) cacheFileName(url string) string {
-	return filepath.Join(config.CacheDir(), "caches", util.SHA256Hash(url).String())
+	return filepath.Join(config.CacheDir(), "caches", shautil.SHA256(url).String())
 }
 
 func (d downloader) cacheDownloadingFileName(url string) string {
diff --git a/util/fsutil/fs.go b/util/fsutil/fs.go
new file mode 100644
index 000000000..5c8a2d9fc
--- /dev/null
+++ b/util/fsutil/fs.go
@@ -0,0 +1,50 @@
+package fsutil
+
+import (
+	"io/fs"
+	"os"
+	"testing/fstest"
+)
+
+// FS is the host filesystem implementation.
+var FS FileSystem = DefaultFS{}
+
+// MkdirAll calls FS.MakedirAll
+func MkdirAll(path string, perm os.FileMode) error { return FS.MkdirAll(path, perm) }
+
+// Open calls FS.Open
+func Open(name string) (fs.File, error) { return FS.Open(name) }
+
+// FS is abstraction for filesystem.
+type FileSystem interface {
+	MkdirAll(path string, perm os.FileMode) error
+	fs.FS
+}
+
+var _ FileSystem = DefaultFS{}
+var _ FileSystem = fakeFS{}
+
+// DefaultFS is the default OS implementation of FileSystem.
+type DefaultFS struct{}
+
+// Open implements FS
+func (DefaultFS) Open(name string) (fs.File, error) { return os.Open(name) }
+
+// MkdirAll implements FS
+func (DefaultFS) MkdirAll(path string, perm fs.FileMode) error { return os.MkdirAll(path, perm) }
+
+// FakeFS is a mock FS. The following can be done in a test before usage.
+//  osutil.FS = osutil.FakeFS
+var FakeFS FileSystem = fakeFS{}
+
+type fakeFS struct{}
+
+// Open implements FileSystem
+func (fakeFS) Open(name string) (fs.File, error) {
+	return fstest.MapFS{name: &fstest.MapFile{
+		Data: []byte("fake file - " + name),
+	}}.Open(name)
+}
+
+// MkdirAll implements FileSystem
+func (fakeFS) MkdirAll(path string, perm fs.FileMode) error { return nil }
diff --git a/util/osutil/os.go b/util/osutil/os.go
new file mode 100644
index 000000000..31efb4336
--- /dev/null
+++ b/util/osutil/os.go
@@ -0,0 +1,48 @@
+package osutil
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	"github.com/sirupsen/logrus"
+)
+
+const EnvColimaBinary = "COLIMA_BINARY"
+
+// Executable returns the path name for the executable that started
+// the current process.
+func Executable() string {
+	e, err := func(s string) (string, error) {
+		// prioritize env var in case this is a nested process
+		if e := os.Getenv(EnvColimaBinary); e != "" {
+			return e, nil
+		}
+
+		if filepath.IsAbs(s) {
+			return s, nil
+		}
+
+		e, err := exec.LookPath(s)
+		if err != nil {
+			return "", fmt.Errorf("error looking up '%s' in PATH: %w", s, err)
+		}
+
+		abs, err := filepath.Abs(e)
+		if err != nil {
+			return "", fmt.Errorf("error computing absolute path of '%s': %w", e, err)
+		}
+
+		return abs, nil
+	}(os.Args[0])
+
+	if err != nil {
+		// this should never happen, thereby it is safe to do
+		logrus.Warnln(fmt.Errorf("cannot detect current running executable: %w", err))
+		logrus.Warnln("falling back to first CLI argument")
+		return os.Args[0]
+	}
+
+	return e
+}
diff --git a/util/shautil/sha.go b/util/shautil/sha.go
new file mode 100644
index 000000000..a69995f76
--- /dev/null
+++ b/util/shautil/sha.go
@@ -0,0 +1,33 @@
+package shautil
+
+import (
+	"crypto/sha1"
+	"crypto/sha256"
+	"fmt"
+)
+
+// SHA is a sha computation
+type SHA interface {
+	String() string
+	Bytes() []byte
+}
+
+type s1 [20]byte
+
+func (s s1) String() string { return fmt.Sprintf("%x", s[:]) }
+func (s s1) Bytes() []byte  { return s[:] }
+
+type s256 [32]byte
+
+func (s s256) String() string { return fmt.Sprintf("%x", s[:]) }
+func (s s256) Bytes() []byte  { return s[:] }
+
+// SHA256Hash computes a sha256sum of a string.
+func SHA256(s string) SHA {
+	return s256(sha256.Sum256([]byte(s)))
+}
+
+// SHA256Hash computes a sha256sum of a string.
+func SHA1(s string) SHA {
+	return s1(sha1.Sum([]byte(s)))
+}
diff --git a/util/util.go b/util/util.go
index 9948bba86..efe6aa059 100644
--- a/util/util.go
+++ b/util/util.go
@@ -1,9 +1,7 @@
 package util
 
 import (
-	"crypto/sha256"
 	"fmt"
-	"log"
 	"net"
 	"os"
 	"runtime"
@@ -18,20 +16,11 @@ func HomeDir() string {
 	home, err := os.UserHomeDir()
 	if err != nil {
 		// this should never happen
-		log.Fatal(fmt.Errorf("error retrieving home directory: %w", err))
+		logrus.Fatal(fmt.Errorf("error retrieving home directory: %w", err))
 	}
 	return home
 }
 
-type SHA256 [32]byte
-
-func (s SHA256) String() string { return fmt.Sprintf("%x", s[:]) }
-
-// SHA256Hash computes a sha256sum of a string.
-func SHA256Hash(s string) SHA256 {
-	return sha256.Sum256([]byte(s))
-}
-
 // MacOS returns if the current OS is macOS.
 func MacOS() bool {
 	return runtime.GOOS == "darwin"
@@ -64,11 +53,11 @@ func RemoveFromPath(path, dir string) string {
 func RandomAvailablePort() int {
 	listener, err := net.Listen("tcp", ":0")
 	if err != nil {
-		log.Fatal(fmt.Errorf("error picking an available port: %w", err))
+		logrus.Fatal(fmt.Errorf("error picking an available port: %w", err))
 	}
 
 	if err := listener.Close(); err != nil {
-		log.Fatal(fmt.Errorf("error closing temporary port listener: %w", err))
+		logrus.Fatal(fmt.Errorf("error closing temporary port listener: %w", err))
 	}
 
 	return listener.Addr().(*net.TCPAddr).Port