nix: add support for nix profile

PR #2833

Co-authored-by: David Arnold <dar@xoe.solutions>
Co-authored-by: Florian Franzen <Florian.Franzen@gmail.com>

(cherry picked from commit 2f58d0a3de)

home-manager/home-manager

@@ -10,6 +10,23 @@ function errorEcho() {
     echo $* >&2
 }
 
+function removeByName() {
+  nix profile list \
+      | { grep "$1" || test $? = 1; } \
+      | cut -d ' ' -f 4 \
+      | xargs -t $DRY_RUN_CMD nix profile remove $VERBOSE_ARG
+}
+
+function setNixProfileCommands() {
+    if [[ -e ~/.nix-profile/manifest.json ]] ; then
+        LIST_OUTPATH_CMD="nix profile list"
+        REMOVE_CMD="removeByName"
+    else
+        LIST_OUTPATH_CMD="nix-env -q --outpath"
+        REMOVE_CMD="nix-env -q"
+    fi
+}
+
 function setVerboseAndDryRun() {
     if [[ -v VERBOSE ]]; then
         export VERBOSE_ARG="--verbose"
@@ -371,8 +388,9 @@ function doExpireGenerations() {
 }
 
 function doListPackages() {
+    setNixProfileCommands
     local outPath
-    outPath="$(nix-env -q --out-path | grep -o '/.*home-manager-path$')"
+    outPath="$($LIST_OUTPATH_CMD | grep -o '/.*home-manager-path$')"
     if [[ -n "$outPath" ]] ; then
         nix-store -q --references "$outPath" | sed 's/[^-]*-//'
     else
@@ -447,6 +465,7 @@ function doShowNews() {
 
 function doUninstall() {
     setVerboseAndDryRun
+    setNixProfileCommands
 
     echo "This will remove Home Manager from your system."
 
@@ -464,7 +483,7 @@ function doUninstall() {
             HOME_MANAGER_CONFIG="$(mktemp --tmpdir home-manager.XXXXXXXXXX)"
             echo "{ lib, ... }: { home.file = lib.mkForce {}; }" > "$HOME_MANAGER_CONFIG"
             doSwitch
-            $DRY_RUN_CMD nix-env -e home-manager-path || true
+            $DRY_RUN_CMD $REMOVE_CMD home-manager-path || true
             rm "$HOME_MANAGER_CONFIG"
             $DRY_RUN_CMD rm $VERBOSE_ARG -r \
                 "${XDG_DATA_HOME:-$HOME/.local/share}/home-manager"

modules/files.nix

@@ -260,7 +260,17 @@ in
 
           if [[ ! -v oldGenPath || "$oldGenPath" != "$newGenPath" ]] ; then
             echo "Creating profile generation $newGenNum"
+            if [[ -e "$genProfilePath"/manifest.json ]] ; then
+              # Remove all packages from "$genProfilePath"
+              # `nix profile remove '.*' --profile "$genProfilePath"` was not working, so here is a workaround:
+              nix profile list --profile "$genProfilePath" \
+                | cut -d ' ' -f 4 \
+                | xargs -t $DRY_RUN_CMD nix profile remove $VERBOSE_ARG --profile "$genProfilePath"
+              $DRY_RUN_CMD nix profile install $VERBOSE_ARG --profile "$genProfilePath" "$newGenPath"
+            else
               $DRY_RUN_CMD nix-env $VERBOSE_ARG --profile "$genProfilePath" --set "$newGenPath"
+            fi
+
             $DRY_RUN_CMD ln -Tsf $VERBOSE_ARG "$newGenPath" "$newGenGcPath"
           else
             echo "No change so reusing latest profile generation $oldGenNum"

modules/home-environment.nix

@@ -578,30 +578,49 @@ in
       if config.submoduleSupport.externalPackageInstall
       then
         ''
+          if [[ -e "$nixProfilePath"/manifest.json ]] ; then
+            nix profile list \
+              | { grep 'home-manager-path$' || test $? = 1; } \
+              | awk -F ' ' '{ print $4 }' \
+              | cut -d ' ' -f 4 \
+              | xargs -t $DRY_RUN_CMD nix profile remove $VERBOSE_ARG
+          else
             if nix-env -q | grep '^home-manager-path$'; then
               $DRY_RUN_CMD nix-env -e home-manager-path
             fi
+          fi
         ''
       else
         ''
-          if ! $DRY_RUN_CMD nix-env -i ${cfg.path} ; then
+          if [[ -e "$nixProfilePath"/manifest.json ]] ; then
+            INSTALL_CMD="nix profile install"
+            LIST_CMD="nix profile list"
+            REMOVE_CMD_SYNTAX='nix profile remove {number | store path}'
+          else
+            INSTALL_CMD="nix-env -i"
+            LIST_CMD="nix-env -q"
+            REMOVE_CMD_SYNTAX='nix-env -e {package name}'
+          fi
+
+          if ! $DRY_RUN_CMD $INSTALL_CMD ${cfg.path} ; then
             cat <<EOF
 
           Oops, nix-env failed to install your new Home Manager profile!
 
           Perhaps there is a conflict with a package that was installed using
-          'nix-env -i'? Try running
+          '$INSTALL_CMD'? Try running
 
-              nix-env -q
+              $LIST_COMMAND
 
           and if there is a conflicting package you can remove it with
 
-              nix-env -e {package name}
+              $REMOVE_CMD_SYNTAX
 
           Then try activating your Home Manager configuration again.
           EOF
             exit 1
           fi
+          unset INSTALL_CMD LIST_CMD REMOVE_CMD_SYNTAX
         ''
     );
 

modules/lib-bash/activation-init.sh

@@ -5,6 +5,7 @@ function setupVars() {
     local profilesPath="$nixStateDir/profiles/per-user/$USER"
     local gcPath="$nixStateDir/gcroots/per-user/$USER"
 
+    declare -gr nixProfilePath="$profilesPath/profile"
     declare -gr genProfilePath="$profilesPath/home-manager"
     declare -gr newGenPath="@GENERATION_DIR@";
     declare -gr newGenGcPath="$gcPath/current-home"