Prefer BAZELISK_HOME with OS postfix

README.md

@@ -181,6 +181,9 @@ The following variables can be set:
 - `BAZELISK_BASE_URL`
 - `BAZELISK_CLEAN`
 - `BAZELISK_GITHUB_TOKEN`
+- `BAZELISK_HOME_DARWIN`
+- `BAZELISK_HOME_LINUX`
+- `BAZELISK_HOME_WINDOWS`
 - `BAZELISK_HOME`
 - `BAZELISK_INCOMPATIBLE_FLAGS`
 - `BAZELISK_SHUTDOWN`
@@ -195,6 +198,8 @@ Configuration variables are evaluated with precedence order. The preferred value
 * Variables defined in the workspace root `.bazeliskrc`
 * Variables defined in the user home `.bazeliskrc`
 
+Additionally, the bazelisk home directory is also evaluated in precedence order. The preffered value is OS-specific e.g. `BAZELISK_HOME_LINUX`, then we fall back to `BAZELISK_HOME`.
+
 ## Requirements
 
 For ease of use, the Python version of Bazelisk is written to work with Python 2.7 and 3.x and only uses modules provided by the standard library.

core/core.go

@@ -91,7 +91,10 @@ func RunBazeliskWithArgsFunc(argsFunc ArgsFunc, repos *Repositories) (int, error
 func RunBazeliskWithArgsFuncAndConfig(argsFunc ArgsFunc, repos *Repositories, config config.Config) (int, error) {
 	httputil.UserAgent = getUserAgent(config)
 
-	bazeliskHome := config.Get("BAZELISK_HOME")
+	bazeliskHome := config.Get("BAZELISK_HOME_" + strings.ToUpper(runtime.GOOS))
+	if len(bazeliskHome) == 0 {
+		bazeliskHome = config.Get("BAZELISK_HOME")
+	}
 	if len(bazeliskHome) == 0 {
 		userCacheDir, err := os.UserCacheDir()
 		if err != nil {