getEnv(): Return std::optional

This allows distinguishing between an empty value and no value.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/nix/doctor.cc b/src/nix/doctor.cc
index 795236c5f..481c93b45 100644
--- a/src/nix/doctor.cc
+++ b/src/nix/doctor.cc
@@ -68,7 +68,7 @@ struct CmdDoctor : StoreCommand
     {
         PathSet dirs;
 
-        for (auto & dir : tokenizeString<Strings>(getEnv("PATH"), ":"))
+        for (auto & dir : tokenizeString<Strings>(getEnv("PATH").value_or(""), ":"))
             if (pathExists(dir + "/nix-env"))
                 dirs.insert(dirOf(canonPath(dir + "/nix-env", true)));
 
@@ -87,7 +87,7 @@ struct CmdDoctor : StoreCommand
     {
         PathSet dirs;
 
-        for (auto & dir : tokenizeString<Strings>(getEnv("PATH"), ":")) {
+        for (auto & dir : tokenizeString<Strings>(getEnv("PATH").value_or(""), ":")) {
             Path profileDir = dirOf(dir);
             try {
                 Path userEnv = canonPath(profileDir, true);