nix: Set profile only with certain goals

src/nix/host.rs

@@ -86,11 +86,13 @@ impl Host for Local {
     }
     async fn activate(&mut self, profile: &StorePath, goal: DeploymentGoal) -> NixResult<()> {
         let profile = profile.as_path().to_str().unwrap();
+        if goal.should_switch_profile() {
             Command::new("nix-env")
                 .args(&["--profile", SYSTEM_PROFILE])
                 .args(&["--set", profile])
                 .passthrough()
                 .await?;
+        }
 
         let activation_command = format!("{}/bin/switch-to-configuration", profile);
         Command::new(activation_command)
@@ -133,8 +135,10 @@ impl Host for SSH {
     async fn activate(&mut self, profile: &StorePath, goal: DeploymentGoal) -> NixResult<()> {
         let profile = profile.as_path().to_str().unwrap();
 
+        if goal.should_switch_profile() {
             let set_profile = self.ssh(&["nix-env", "--profile", SYSTEM_PROFILE, "--set", profile]);
             self.run_command(set_profile).await?;
+        }
 
         let activation_command = format!("{}/bin/switch-to-configuration", profile);
         let command = self.ssh(&[&activation_command, goal.as_str().unwrap()]);

src/nix/mod.rs

@@ -207,6 +207,14 @@ impl DeploymentGoal {
             DryActivate => Some("Dry activation successful"),
         }
     }
+
+    pub fn should_switch_profile(&self) -> bool {
+        use DeploymentGoal::*;
+        match self {
+            Boot | Switch => true,
+            _ => false,
+        }
+    }
 }
 
 struct NixInstantiate<'hive> {