Unify home directory handling.

The `std::env::home_dir()` function is deprecated (as of 1.29.0)
due to potentially "surprising" behaviour.  The compiler recommends
we switch to `dirs::home_dir()` so this commit does just that.

In addition, we risked diverging in behaviour because rustup-utils
has its own `home_dir()` behaviour for Windows, so change rustup-cli
to use that too.

Author: kinnison

src/rustup-cli/self_update.rs

@@ -383,9 +383,9 @@ fn do_pre_install_sanity_checks() -> Result<()> {
     let multirust_manifest_path = PathBuf::from("/usr/local/lib/rustlib/manifest-multirust");
     let rustc_manifest_path = PathBuf::from("/usr/local/lib/rustlib/manifest-rustc");
     let uninstaller_path = PathBuf::from("/usr/local/lib/rustlib/uninstall.sh");
-    let multirust_meta_path = env::home_dir().map(|d| d.join(".multirust"));
+    let multirust_meta_path = utils::home_dir().map(|d| d.join(".multirust"));
     let multirust_version_path = multirust_meta_path.as_ref().map(|p| p.join("version"));
-    let rustup_sh_path = env::home_dir().map(|d| d.join(".rustup"));
+    let rustup_sh_path = utils::home_dir().map(|d| d.join(".rustup"));
     let rustup_sh_version_path = rustup_sh_path.as_ref().map(|p| p.join("rustup-version"));
 
     let multirust_exists = multirust_manifest_path.exists() && uninstaller_path.exists();

src/rustup-utils/Cargo.toml

@@ -23,6 +23,7 @@ semver = "0.9.0"
 sha2 = "0.7.0"
 toml = "0.4"
 url = "1.1"
+dirs = "1.0"
 
 [target."cfg(windows)".dependencies]
 winapi = { version = "0.3", features = ["combaseapi", "errhandlingapi", "fileapi", "handleapi",

src/rustup-utils/src/utils.rs

@@ -522,7 +522,7 @@ where
 
 #[cfg(unix)]
 pub fn home_dir() -> Option<PathBuf> {
-    ::std::env::home_dir()
+    dirs::home_dir()
 }
 
 pub fn cargo_home() -> Result<PathBuf> {