Revert "pin channels using nix.nixPath rather than using ~/.nix-defexpr"

This reverts commit 4e5e1bca6c94b922e906549683e1780a1d49d02f.

1 files changed, 46 insertions, 8 deletions

diff --git a/bin/home-manager b/bin/home-manager
index 70ef9064..5e10bc77 100755
--- a/bin/home-manager
+++ b/bin/home-manager
@@ -31,13 +31,40 @@ for i in 1
         echo "user home-manager configuration folder $hm_config_dir does not exist, creating it"
         mkdir -p $hm_config_dir
     end
-    if test -e $channel_root
-        if test ! -L $channel_root
-            rm $channel_root/* || exit 1
-            rmdir $channel_root
+    if test ! -e $channel_root
+        if test -L $channel_root
+            # broken symlink
+            rm $channel_root
+        end
+        echo "channel root $channel_root does not exist, creating it"
+        mkdir -p $channel_root
+    else
+        if test ! -d $channel_root
+            echo "error: $channel_root is not a directory"
+        else if test -L $channel_root
+            echo "error: $channel_root is a symlink, please remove it"
+        else if path is --invert --perm write $channel_root
+            echo "error: $channel_root is not writable; might be a symlink"
+        else if path is --invert --type link $channel_root/*
+            for p in (path filter --invert --type link $channel_root/*)
+                # might be a broken symlink
+                if test -L $p -a ! -e $p
+                    rm $p
+                else
+                    echo "error: channel $p is not a broken symlink, don't know what to do with it"
+                end
+            end
+            # check again and fail if there are still unknown files
+            if path is --invert --type link $channel_root/*
+                echo "error: non-link(s) in $channel_root"
+                path filter --invert --type link $channel_root/*
+            else
+                continue
+            end
         else
-            rm $channel_root || exit 1
+            continue # with script
         end
+        exit 1
     end
 end
 
@@ -69,6 +96,8 @@ switch $current_script_name
         set --export HOME_MANAGER_CONFIG $hm_config_source
 end
 
+set --function old_channels (path basename $channel_root/*)
+
 function update_link --argument-names new_src target
     set --function current_src (path resolve $target)
     if test -e $current_src
@@ -83,12 +112,21 @@ function update_link --argument-names new_src target
 end
 
 for np in $NIX_PATH
-    echo $np | read --function --delimiter "=" channel new_src
+    echo $np | read --function --delimiter "=" channel new_src_rel
+    set --local new_src (path resolve $new_src_rel)
 
-    if test $channel = nixpkgs-overlays
-        update_link $new_src $user_nixpkgs/overlays
+    if test $channel = darwin-config
         continue
     end
+    if set --local i (contains --index $channel $old_channels)
+        set --erase old_channels[$i]
+    end
+
+    update_link $new_src $channel_root/$channel
+end
+
+for old in $channel_root/$old_channels
+    rm $old
 end
 
 set --function i (contains --index (status dirname) $PATH)