persist ~/.cache/nix

```
• Updated input 'nixpkgs-stable':
    'github:NixOS/nixpkgs/6a3f9996408c970b99b8b992b11bb249d1455b62' (2023-01-12)
  → 'github:NixOS/nixpkgs/e285dd0ca97c264003867c7329f0d1f4f028739c' (2023-01-13)
• Updated input 'nixpkgs-unpatched':
    'github:NixOS/nixpkgs/6c8644fc37b6e141cbfa6c7dc8d98846c4ff0c2e' (2023-01-11)
  → 'github:NixOS/nixpkgs/0f213d0fee84280d8c3a97f7469b988d6fe5fcdf' (2023-01-12)
```

flake.lock

@@ -71,11 +71,11 @@
     },
     "nixpkgs-stable": {
       "locked": {
-        "lastModified": 1673527292,
-        "narHash": "sha256-903EpRSDCfUvic7Hsiqwy+h7zlMTLAUbCXkEGGriCfM=",
+        "lastModified": 1673612960,
+        "narHash": "sha256-DWR7hrbecJKmUJCswk9MXZta710mq+3jZwTvHU/UfyY=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "6a3f9996408c970b99b8b992b11bb249d1455b62",
+        "rev": "e285dd0ca97c264003867c7329f0d1f4f028739c",
         "type": "github"
       },
       "original": {
@@ -102,11 +102,11 @@
     },
     "nixpkgs-unpatched": {
       "locked": {
-        "lastModified": 1673450908,
-        "narHash": "sha256-b8em+kwrNtnB7gR8SyVf6WuTyQ+6tHS6dzt9D9wgKF0=",
+        "lastModified": 1673540789,
+        "narHash": "sha256-xqnxBOK3qctIeUVxecydrEDbEXjsvHCPGPbvsl63M/U=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "6c8644fc37b6e141cbfa6c7dc8d98846c4ff0c2e",
+        "rev": "0f213d0fee84280d8c3a97f7469b988d6fe5fcdf",
         "type": "github"
       },
       "original": {

flake.nix

@@ -1,4 +1,13 @@
-# docs:
+# FLAKE FEEDBACK:
+# - flake input url schemes (like `github:nixos/nixpkgs`, or `nixpkgs/nixos-22.11`) are confusing and opaque.
+#   - use established URI formats like https://github.com/<owner>/<repo>.
+#   - or reuse `fetchGit*` idioms from nixpkgs.
+#   - but please don't just invent something new.
+# - need a way to apply local patches to inputs.
+#   - this could be part of the `inputs` proper, or something like `builtins.applyPatches`.
+#
+#
+# DEVELOPMENT DOCS:
 # - <https://nixos.wiki/wiki/Flakes>
 # - <https://serokell.io/blog/practical-nix-flakes>
 

hosts/common/users.nix

@@ -86,6 +86,7 @@ in
       "Pictures"
       "Videos"
 
+      ".cache/nix"
       ".cargo"
       ".rustup"
     ];

modules/gui/snippets.txt

@@ -1,6 +1,7 @@
 https://search.nixos.org/options?channel=unstable&query=
 https://search.nixos.org/packages?channel=unstable&query=
 https://nixos.wiki/index.php?go=Go&search=
+https://nixos.org/manual/nix/stable/language/builtins.html
 https://github.com/nixos/nixpkgs/pulls?q=
 https://nur.nix-community.org/
 https://nix-community.github.io/home-manager/options.html

modules/packages.nix

@@ -102,7 +102,9 @@ let
     gnome.gnome-terminal  # works on phosh
     gnome.gnome-weather
 
-    { pkg = gpodder-configured; dir = [ "gPodder/Downloads" ]; }
+    # XXX: we preserve the whole thing because if we only preserve gPodder/Downloads
+    #   then startup is SLOW during feed import, and we might end up with zombie eps in the dl dir.
+    { pkg = gpodder-configured; dir = [ "gPodder" ]; }
 
     gthumb
     handbrake

pkgs/gpodder-configured/default.nix

@@ -1,22 +1,28 @@
 { makeWrapper
 , gpodder
+, linkFarm
 , symlinkJoin
-, writeShellScript
-, config
 }:
 
+let
+  remove-extra = linkFarm "gpodder-remove-extra" [
+    { name = "bin/gpodder-remove-extra"; path = ./remove_extra.py; }
+  ];
+in
+# we use a symlinkJoin so that we can inherit the .desktop and icon files from the original gPodder
 (symlinkJoin {
   name = "gpodder-configured";
-  paths = [ gpodder ];
+  paths = [ gpodder remove-extra ];
   buildInputs = [ makeWrapper ];
 
   # gpodder keeps all its feeds in a sqlite3 database.
   # we can configure the feeds externally by wrapping gpodder and just instructing it to import
   # a feedlist every time we run it.
-  # repeat imports are deduplicated -- assuming network access (not sure how it behaves when disconnected).
+  # repeat imports are deduplicated by url, even when offline.
   postBuild = ''
     makeWrapper $out/bin/gpodder $out/bin/gpodder-configured \
-      --run "$out/bin/gpo import ~/.config/gpodderFeeds.opml"
+      --run "$out/bin/gpodder-remove-extra ~/.config/gpodderFeeds.opml" \
+      --run "$out/bin/gpo import ~/.config/gpodderFeeds.opml" \
 
     # fix up the .desktop file to invoke our wrapped application
     orig_desktop=$(readlink $out/share/applications/gpodder.desktop)

pkgs/gpodder-configured/remove_extra.py

@@ -0,0 +1,79 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i python3 -p "python3.withPackages (ps: [gnome-feeds.listparser])" -p gpodder
+
+from dataclasses import dataclass, field
+import listparser
+import subprocess
+import sys
+
+@dataclass(repr=True)
+class Feed:
+    url: str
+    title: str  # Optional
+    def __init__(self, url: str, title: str):
+        self.url = url
+        self.title = title if title else None
+
+    def __eq__(self, other: 'Feed') -> bool:
+        return self.url == other.url and \
+            (self.title == other.title or None in [self.title, other.title])
+
+@dataclass(init=True)
+class Partitioned:
+    has_not_wanted: list[Feed] = field(default_factory=list)
+    wanted_not_has: list[Feed] = field(default_factory=list)
+    intersection:   list[Feed] = field(default_factory=list)
+
+
+def wanted_feeds(opml_file: str):
+    parsed = listparser.parse(open(opml_file).read())
+    return [Feed(url=p['url'], title=p['title']) for p in parsed.feeds]
+
+def has_feeds():
+    listing = subprocess.check_output(["gpo", "list"]).decode()
+    feeds = []
+
+    title = None
+    for line in listing.split("\n"):
+        if line.startswith("# "):  # title
+            title = line[2:].strip()
+        elif line.startswith("http"):  # feed URL:
+            feeds.append(Feed(url=line, title=title))
+            title = None
+
+    return feeds
+
+def partition_feeds(wanted: list[Feed], has: list[Feed]) -> Partitioned:
+    p = Partitioned()
+    for f in wanted + has:
+        w, h = f in wanted, f in has
+        if h and not w:
+            p.has_not_wanted.append(f)
+        elif w and not h:
+            p.wanted_not_has.append(f)
+        else:
+            assert w and h
+            p.intersection.append(f)
+
+    return p
+
+def remove_feed(feed: Feed):
+    subprocess.check_output(['gpo', 'unsubscribe', feed.url])
+
+def rationalize_feeds(opml_file: str):
+    wanted = wanted_feeds(opml_file)
+    has = has_feeds()
+    partitioned = partition_feeds(wanted, has)
+
+    print("extra feeds:", "" if partitioned.has_not_wanted else "(none)")
+    for f in partitioned.has_not_wanted:
+        print("  ", f)
+    print()
+
+    for f in partitioned.has_not_wanted:
+        remove_feed(f)
+
+if __name__ == "__main__":
+    wanted_opml, = sys.argv[1:]
+    rationalize_feeds(wanted_opml)
+

pkgs/sane-scripts/src/sane-bt-search

@@ -1,4 +1,5 @@
-#!/usr/bin/env python
+#!/usr/bin/env nix-shell
+#!nix-shell -i python3 -p "python3.withPackages (ps: [ ps.natsort ps.requests ])"
 """
 usage: sane-bt-search <query_string>
 
@@ -67,5 +68,6 @@ q = " ".join(sys.argv[1:])
 
 client = Client()
 res = client.query(q)
+print(f"found {len(res)} result(s)")
 for r in res[:5]:
     print(r)