no panic if HOME does not exist (#2148)

* no home dir exist

* dolt root can be empty

* move test to bottom

* dir -> directory

* Windows complaining about smth

go/cmd/dolt/dolt.go

@@ -236,6 +236,7 @@ func runMain() int {
 	root, err := env.GetCurrentUserHomeDir()
 
 	if err != nil {
+		cli.PrintErrln(color.RedString("Failed to load the HOME directory: %v", err))
 		return 1
 	}
 

go/libraries/doltcore/env/paths.go

@@ -44,14 +44,21 @@ func GetCurrentUserHomeDir() (string, error) {
 	if doltRootPath, ok := os.LookupEnv(doltRootPathEnvVar); ok && doltRootPath != "" {
 		return doltRootPath, nil
 	}
+
+	var home string
 	if homeEnvPath, ok := os.LookupEnv(homeEnvVar); ok && homeEnvPath != "" {
-		return homeEnvPath, nil
-	}
-	if usr, err := user.Current(); err != nil {
+		home = homeEnvPath
+	} else if usr, err := user.Current(); err != nil {
 		return "", err
 	} else {
-		return usr.HomeDir, nil
+		home = usr.HomeDir
 	}
+
+	_, err := os.Stat(home)
+	if err != nil {
+		return "", err
+	}
+	return home, nil
 }
 
 func getCredsDir(hdp HomeDirProvider) (string, error) {

integration-tests/bats/no-repo.bats

@@ -272,3 +272,13 @@ NOT_VALID_REPO_ERROR="The current directory is not a valid dolt repository."
     run dolt checkout help
     [ "$status" -ne 0 ]
 }
+
+@test "no-repo: don't panic if invalid HOME" {
+    DOLT_ROOT_PATH=
+    HOME=/this/is/garbage
+    run dolt
+    [ "$status" -eq 1 ]
+    [[ ! "$output" =~ "panic" ]]
+    [[ "$output" =~ "Failed to load the HOME directory" ]]
+}
+