Search for the data directory using argv[0] *and* os.Executable()

Some version managers like aqua rely on shims in $PATH to run the proper
application. This isn't particularly unusual, but it was broken by the
changes in #3566, because directory lookup ends up pointing to *the
shim* rather than the underlying installation.

The existing logic already has the concept of falling back to
os.Executable if a path based on `argv[0]` can't be determined, so this
issue can be solved by just always checking os.Executable *in addition*
to `argv[0]`.

Signed-off-by: re:fi.64 <hello@refi64.dev>

Author: refi64

pkg/usrlocalsharelima/usrlocalsharelima.go

@@ -23,32 +23,42 @@ import (
 // It will also append the file extension on Windows, if necessary.
 // This function is different from os.Executable(), which will use /proc/self/exe on Linux
 // and therefore will resolve any symlink used to locate the executable. This function will
-// return the symlink instead because we want to locate ../share/lima relative to the location
-// of the symlink, and not the actual executable. This is important when using Homebrew.
-//
-// If os.Args[0] is invalid, this function still falls back on os.Executable().
+// return the symlink instead because we want to be able to locate ../share/lima relative
+// to the location of the symlink, and not the actual executable. This is important when
+// using Homebrew.
 var executableViaArgs0 = sync.OnceValues(func() (string, error) {
 	if os.Args[0] == "" {
-		logrus.Warn("os.Args[0] has not been set")
-	} else {
-		executable, err := exec.LookPath(os.Args[0])
-		if err == nil {
-			// LookPath() will add the `.exe` file extension on Windows, but will not return an
-			// absolute path if the argument contained any of `:/\` (or just `/` on Unix).
-			return filepath.Abs(executable)
-		}
-		logrus.Warnf("os.Args[0] is invalid: %v", err)
+		return "", errors.New("os.Args[0] has not been set")
+	}
+	executable, err := exec.LookPath(os.Args[0])
+	if err == nil {
+		executable, err = filepath.Abs(executable)
+	}
+	if err != nil {
+		return "", fmt.Errorf("os.Args[0] is invalid: %w", err)
 	}
-	return os.Executable()
+
+	return executable, nil
 })
 
 // Dir returns the location of the <PREFIX>/lima/share directory, relative to the location
 // of the current executable. It checks for multiple possible filesystem layouts and returns
 // the first candidate that contains the native guest agent binary.
 func Dir() (string, error) {
-	self, err := executableViaArgs0()
+	selfPaths := []string{}
+
+	selfViaArgs0, err := executableViaArgs0()
 	if err != nil {
-		return "", err
+		logrus.WithError(err).Warn("failed to find executable from os.Args[0]")
+	} else {
+		selfPaths = append(selfPaths, selfViaArgs0)
+	}
+
+	selfViaOS, err := os.Executable()
+	if err != nil {
+		logrus.WithError(err).Warn("failed to find os.Executable()")
+	} else if len(selfPaths) == 0 || selfViaOS != selfPaths[0] {
+		selfPaths = append(selfPaths, selfViaOS)
 	}
 
 	ostype := limayaml.NewOS("linux")
@@ -57,31 +67,35 @@ func Dir() (string, error) {
 		return "", fmt.Errorf("failed to get arch for %q", runtime.GOARCH)
 	}
 
-	// self:  /usr/local/bin/limactl
-	selfDir := filepath.Dir(self)
-	selfDirDir := filepath.Dir(selfDir)
-	gaCandidates := []string{
-		// candidate 0:
-		// - self:  /Applications/Lima.app/Contents/MacOS/limactl
-		// - agent: /Applications/Lima.app/Contents/MacOS/lima-guestagent.Linux-x86_64
-		// - dir:   /Applications/Lima.app/Contents/MacOS
-		filepath.Join(selfDir, "lima-guestagent."+ostype+"-"+arch),
-		// candidate 1:
-		// - self:  /usr/local/bin/limactl
-		// - agent: /usr/local/share/lima/lima-guestagent.Linux-x86_64
-		// - dir:   /usr/local/share/lima
-		filepath.Join(selfDirDir, "share/lima/lima-guestagent."+ostype+"-"+arch),
-		// TODO: support custom path
-	}
-	if debugutil.Debug {
-		// candidate 2: launched by `~/go/bin/dlv dap`
-		// - self: ${workspaceFolder}/cmd/limactl/__debug_bin_XXXXXX
-		// - agent: ${workspaceFolder}/_output/share/lima/lima-guestagent.Linux-x86_64
-		// - dir:  ${workspaceFolder}/_output/share/lima
-		candidateForDebugBuild := filepath.Join(filepath.Dir(selfDirDir), "_output/share/lima/lima-guestagent."+ostype+"-"+arch)
-		gaCandidates = append(gaCandidates, candidateForDebugBuild)
-		logrus.Infof("debug mode detected, adding more guest agent candidates: %v", candidateForDebugBuild)
+	gaCandidates := []string{}
+	for _, self := range selfPaths {
+		// self:  /usr/local/bin/limactl
+		selfDir := filepath.Dir(self)
+		selfDirDir := filepath.Dir(selfDir)
+		gaCandidates = append(gaCandidates,
+			// candidate 0:
+			// - self:  /Applications/Lima.app/Contents/MacOS/limactl
+			// - agent: /Applications/Lima.app/Contents/MacOS/lima-guestagent.Linux-x86_64
+			// - dir:   /Applications/Lima.app/Contents/MacOS
+			filepath.Join(selfDir, "lima-guestagent."+ostype+"-"+arch),
+			// candidate 1:
+			// - self:  /usr/local/bin/limactl
+			// - agent: /usr/local/share/lima/lima-guestagent.Linux-x86_64
+			// - dir:   /usr/local/share/lima
+			filepath.Join(selfDirDir, "share/lima/lima-guestagent."+ostype+"-"+arch),
+			// TODO: support custom path
+		)
+		if debugutil.Debug {
+			// candidate 2: launched by `~/go/bin/dlv dap`
+			// - self: ${workspaceFolder}/cmd/limactl/__debug_bin_XXXXXX
+			// - agent: ${workspaceFolder}/_output/share/lima/lima-guestagent.Linux-x86_64
+			// - dir:  ${workspaceFolder}/_output/share/lima
+			candidateForDebugBuild := filepath.Join(filepath.Dir(selfDirDir), "_output/share/lima/lima-guestagent."+ostype+"-"+arch)
+			gaCandidates = append(gaCandidates, candidateForDebugBuild)
+			logrus.Infof("debug mode detected, adding more guest agent candidates: %v", candidateForDebugBuild)
+		}
 	}
+
 	for _, gaCandidate := range gaCandidates {
 		if _, err := os.Stat(gaCandidate); err == nil {
 			return filepath.Dir(gaCandidate), nil
@@ -95,8 +109,8 @@ func Dir() (string, error) {
 		}
 	}
 
-	return "", fmt.Errorf("failed to find \"lima-guestagent.%s-%s\" binary for %q, attempted %v",
-		ostype, arch, self, gaCandidates)
+	return "", fmt.Errorf("failed to find \"lima-guestagent.%s-%s\" binary for %v, attempted %v",
+		ostype, arch, selfPaths, gaCandidates)
 }
 
 // GuestAgentBinary returns the absolute path of the guest agent binary, possibly with ".gz" suffix.