[wrappers] Improve wrappers in multi-project env (#1067)

## Summary

This is a possible cause of
#881 (comment)

bin wrappers belong to a specific project so we should not have a single
global hash.

## How was it tested?

`devbox shell`
called binaries, inspected wrappers
`devbox add curl`
called binaries, inspected wrappers

Author: mikeland73

internal/impl/devbox.go

@@ -305,7 +305,12 @@ func (d *Devbox) ShellEnvHash(ctx context.Context) (string, error) {
 		return "", err
 	}
 
-	return envs[devboxShellEnvHashVarName], nil
+	return envs[d.ShellEnvHashKey()], nil
+}
+
+func (d *Devbox) ShellEnvHashKey() string {
+	// Don't make this a const so we don't use it by itself accidentally
+	return "__DEVBOX_SHELLENV_HASH_" + d.projectDirHash()
 }
 
 func (d *Devbox) Info(pkg string, markdown bool) error {
@@ -827,7 +832,7 @@ func (d *Devbox) computeNixEnv(ctx context.Context, usePrintDevEnvCache bool) (m
 		os.Getenv("XDG_DATA_DIRS"),
 	)
 
-	return env, addHashToEnv(env)
+	return env, d.addHashToEnv(env)
 }
 
 var nixEnvCache map[string]string
@@ -1113,10 +1118,10 @@ func (d *Devbox) projectDirHash() string {
 	return hash
 }
 
-func addHashToEnv(env map[string]string) error {
+func (d *Devbox) addHashToEnv(env map[string]string) error {
 	hash, err := cuecfg.Hash(env)
 	if err == nil {
-		env[devboxShellEnvHashVarName] = hash
+		env[d.ShellEnvHashKey()] = hash
 	}
 	return err
 }

internal/impl/envvars.go

@@ -11,7 +11,6 @@ import (
 )
 
 const devboxSetPrefix = "__DEVBOX_SET_"
-const devboxShellEnvHashVarName = "__DEVBOX_SHELLENV_HASH"
 
 func mapToPairs(m map[string]string) []string {
 	pairs := []string{}

internal/wrapnix/wrapper.go

@@ -23,6 +23,7 @@ import (
 type devboxer interface {
 	NixBins(ctx context.Context) ([]string, error)
 	ShellEnvHash(ctx context.Context) (string, error)
+	ShellEnvHashKey() string
 	ProjectDir() string
 	Services() (services.Services, error)
 }
@@ -53,20 +54,20 @@ func CreateWrappers(ctx context.Context, devbox devboxer) error {
 	bashPath := cmdutil.GetPathOrDefault("bash", "/bin/bash")
 	for _, service := range services {
 		if err = createWrapper(&createWrapperArgs{
+			devboxer:     devbox,
 			BashPath:     bashPath,
 			Command:      service.Start,
 			Env:          service.Env,
-			ProjectDir:   devbox.ProjectDir(),
 			ShellEnvHash: shellEnvHash,
 			destPath:     filepath.Join(destPath, service.StartName()),
 		}); err != nil {
 			return err
 		}
 		if err = createWrapper(&createWrapperArgs{
+			devboxer:     devbox,
 			BashPath:     bashPath,
 			Command:      service.Stop,
 			Env:          service.Env,
-			ProjectDir:   devbox.ProjectDir(),
 			ShellEnvHash: shellEnvHash,
 			destPath:     filepath.Join(destPath, service.StopName()),
 		}); err != nil {
@@ -81,9 +82,9 @@ func CreateWrappers(ctx context.Context, devbox devboxer) error {
 
 	for _, bin := range bins {
 		if err = createWrapper(&createWrapperArgs{
+			devboxer:     devbox,
 			BashPath:     bashPath,
 			Command:      bin,
-			ProjectDir:   devbox.ProjectDir(),
 			ShellEnvHash: shellEnvHash,
 			destPath:     filepath.Join(destPath, filepath.Base(bin)),
 		}); err != nil {
@@ -95,10 +96,10 @@ func CreateWrappers(ctx context.Context, devbox devboxer) error {
 }
 
 type createWrapperArgs struct {
+	devboxer
 	BashPath     string
 	Command      string
 	Env          map[string]string
-	ProjectDir   string
 	ShellEnvHash string
 
 	destPath string

internal/wrapnix/wrapper.sh.tmpl

@@ -14,14 +14,14 @@ fi
 {{- end }}
 
 {{/*
-We use __DEVBOX_SHELLENV_HASH to avoid re-sourcing shellenv. Since wrappers
+We use ShellEnvHashKey to avoid re-sourcing shellenv. Since wrappers
 call other wrappers and potentially modify the environment, we don't want the
 environment to get re-written.
 
 DO_NOT_TRACK=1 can be removed once we optimize segment to queue events.
 */ -}}
 
-if [[ "$__DEVBOX_SHELLENV_HASH" != "{{ .ShellEnvHash }}" ]]; then
+if [[ "${{ .ShellEnvHashKey }}" != "{{ .ShellEnvHash }}" ]]; then
 eval "$(DO_NOT_TRACK=1 devbox shellenv -c {{ .ProjectDir }})"
 fi