Name the closure's own context where the framework now demands one

Stage 4 of decision 0023, finished. The dependency swap itself compiled the
whole closure on the first attempt; what did not compile was `apps/lumbridge`,
and the entire API delta across a ten-month jump turned out to be three
signatures over 19 call sites.

`Window::focus` is now `focus(&mut self, handle: &FocusHandle, cx: &mut App)`
-- 16 sites. `flex_shrink()` takes the factor it used to assume, so it is
`flex_shrink(1.0)` -- 2 sites. `Application::new()` is gone with the rest of
the entry point, and is `gpui_platform::application()` -- 1 site. That is all
of it. Nothing else in the framework's surface moved under this product in ten
months.

The interesting failure was in the fix, not the framework. Adding `, cx` to
every `window.focus` site is right in a method that owns a `cx` parameter and
wrong inside `cx.listener(...)`, whose closure is handed its own context as a
fourth argument that this code discarded as `_`. One such site capturing the
outer `cx` produced 35 errors -- E0596, two E0521s, an E0500, thirty E0501s and
two E0524s -- none of which named the actual mistake, and all of which vanished
when the discarded parameter was given the name it should have had. Worth
recording: a borrow-checker avalanche after a dependency bump is far more
likely to be one wrong capture than a framework that changed its ownership
model.

No crate outside `apps/lumbridge` needed a single change, because none of them
imports a gpui type. That boundary was not designed for this and paid for
itself anyway.

`scripts/workspace-guard.sh` now asserts what it exists to assert. It compared
`gpui` against version 0.2.2 from the crates.io registry, which after the swap
was a guard that would have failed on the correct state of the tree. It now
checks that `gpui` and `gpui_platform` both carry
git+https://github.com/zed-industries/zed.git at rev ce48461e -- the same rev,
because the pair are one framework snapshot and a disagreement between them
would compile against two. Their versions (0.2.2 and 0.1.0) are deliberately
not asserted; neither has been bumped upstream in ten months and neither means
anything. Both failure modes were induced before being trusted: a wrong
expected rev fails on both packages, and a lockfile where only gpui_platform's
rev is altered fails on that package alone.

One thing to fix next, not here: `cargo deny check sources` now fails. Decision
0023 predicted the move would bring two Git sources; the resolved graph brings
four. wasm_thread (via gpui_web and scheduler) and xim-rs, which supplies
zed-xim, xim-ctext and xim-parser to gpui_linux, are both unallowed, and
zed-industries/scap is in the lockfile too. deny.toml is named in AGENTS.md as
a file a decision record governs, so it is left alone and reported rather than
edited underneath this commit.

The UI gate is green: workspace-guard, fmt, clippy with -D warnings over
--all-targets --all-features, and 79 tests passing.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SPYebLiN2w4TqnHUYGdECq

apps/lumbridge/Cargo.toml

@@ -8,7 +8,13 @@ license.workspace = true
 repository.workspace = true
 
 [dependencies]
-gpui = "0.2.2"
+# Pinned to a full revision by decision 0023. crates.io publishing of gpui
+# stopped in October 2025, the platform backends moved into crates Zed does
+# not publish, and gpui's own x11/wayland features became empty markers
+# there -- so the published crate can no longer build a Linux shell at all.
+# Both crates must carry the SAME rev; workspace-guard.sh asserts it.
+gpui = { git = "https://github.com/zed-industries/zed.git", rev = "ce48461eaadd16c65c31f835511ab96bd3b6e746", default-features = false, features = ["wayland", "x11"] }
+gpui_platform = { git = "https://github.com/zed-industries/zed.git", rev = "ce48461eaadd16c65c31f835511ab96bd3b6e746", default-features = false, features = ["font-kit", "wayland", "x11"] }
 lumbridge-core = { path = "../../crates/lumbridge-core" }
 lumbridge-harness = { path = "../../crates/lumbridge-harness" }
 lumbridge-runtime = { path = "../../crates/lumbridge-runtime" }

apps/lumbridge/src/main.rs

@@ -16,9 +16,13 @@ use std::collections::BTreeMap;
 use std::time::Duration;
 
 use gpui::{
-    App, Application, Bounds, Context, FocusHandle, FontWeight, KeyDownEvent, Pixels, Rgba, Size,
+    App, Bounds, Context, FocusHandle, FontWeight, KeyDownEvent, Pixels, Rgba, Size, Window,
-    Window, WindowBounds, WindowOptions, actions, div, prelude::*, px, relative, rgb, size,
+    WindowBounds, WindowOptions, actions, div, prelude::*, px, relative, rgb, size,
 };
+// The application entry point lives in the platform crate at this revision, not
+// in gpui itself: the backends moved out of the publishable crate, and the
+// constructor moved with them. See decision 0023.
+use gpui_platform::application;
 use lumbridge_core::UsageProvenance;
 use lumbridge_runtime::{
     CommandConfig, PtyOptions, RuntimeActorError, RuntimeActorOptions, RuntimeCommand,
@@ -466,7 +470,7 @@ impl LumbridgeShell {
 impl LumbridgeShell {
     fn new(window: &mut Window, cx: &mut Context<Self>) -> Self {
         let root_focus = cx.focus_handle();
-        window.focus(&root_focus);
+        window.focus(&root_focus, cx);
 
         Self::drive_synthetic_surfaces(cx);
         Self::poll_runtime_events(cx);
@@ -765,7 +769,7 @@ impl LumbridgeShell {
         if self.panels.select(pane) {
             self.persist_panels();
         }
-        window.focus(&self.root_focus);
+        window.focus(&self.root_focus, cx);
         cx.notify();
     }
 
@@ -785,7 +789,7 @@ impl LumbridgeShell {
         if self.panels.select(pane) {
             self.persist_panels();
         }
-        window.focus(&self.root_focus);
+        window.focus(&self.root_focus, cx);
         cx.notify();
     }
 
@@ -806,7 +810,7 @@ impl LumbridgeShell {
         if self.panels.select(pane) {
             self.persist_panels();
         }
-        window.focus(&self.root_focus);
+        window.focus(&self.root_focus, cx);
         cx.notify();
     }
 
@@ -815,7 +819,7 @@ impl LumbridgeShell {
         if self.panels.select_attached_at(index) {
             self.persist_panels();
         }
-        window.focus(&self.root_focus);
+        window.focus(&self.root_focus, cx);
         cx.notify();
     }
 
@@ -835,7 +839,7 @@ impl LumbridgeShell {
             self.persist_panels();
             self.resize_terminal_for_workspace(window, cx);
         }
-        window.focus(&self.root_focus);
+        window.focus(&self.root_focus, cx);
         cx.notify();
     }
 
@@ -858,7 +862,7 @@ impl LumbridgeShell {
         self.add_panel_chooser_open = false;
         self.persist_panels();
         self.resize_terminal_for_workspace(window, cx);
-        window.focus(&self.root_focus);
+        window.focus(&self.root_focus, cx);
         cx.notify();
     }
 
@@ -868,7 +872,7 @@ impl LumbridgeShell {
             self.persist_panels();
             self.resize_terminal_for_workspace(window, cx);
         }
-        window.focus(&self.root_focus);
+        window.focus(&self.root_focus, cx);
         cx.notify();
     }
 
@@ -906,7 +910,7 @@ impl LumbridgeShell {
         self.live_terminals.insert(pane, terminal);
         self.attention.clear(pane);
         self.pending_terminate = None;
-        window.focus(&self.root_focus);
+        window.focus(&self.root_focus, cx);
         cx.notify();
     }
 
@@ -935,7 +939,7 @@ impl LumbridgeShell {
                 Err(error) => LiveRuntimeStatus::Fault(error.to_string()),
             };
         }
-        window.focus(&self.root_focus);
+        window.focus(&self.root_focus, cx);
         cx.notify();
     }
 
@@ -977,7 +981,7 @@ impl LumbridgeShell {
             Some(_) => None,
             None => Some(Page::UsageAndQuota),
         };
-        window.focus(&self.root_focus);
+        window.focus(&self.root_focus, cx);
         cx.notify();
     }
 
@@ -1096,7 +1100,7 @@ impl LumbridgeShell {
             let rows = sidebar::model::flatten(&self.sidebar_input(), &self.sidebar);
             self.sidebar.cursor = sidebar::model::move_cursor(&rows, None, 1);
         }
-        window.focus(&self.root_focus);
+        window.focus(&self.root_focus, cx);
         cx.notify();
     }
 
@@ -1174,7 +1178,7 @@ impl LumbridgeShell {
     fn add_panel_action(&mut self, _: &AddPanel, window: &mut Window, cx: &mut Context<Self>) {
         self.dispatch(ShellAction::CloseCommandPalette);
         self.add_panel_chooser_open = !self.add_panel_chooser_open;
-        window.focus(&self.root_focus);
+        window.focus(&self.root_focus, cx);
         cx.notify();
     }
 
@@ -1192,7 +1196,7 @@ impl LumbridgeShell {
         if self.panels.move_horizontal(delta) {
             self.persist_panels();
         }
-        window.focus(&self.root_focus);
+        window.focus(&self.root_focus, cx);
         cx.notify();
     }
 
@@ -2591,7 +2595,7 @@ impl LumbridgeShell {
                     .on_click(cx.listener(|shell, _, window, cx| {
                         shell.dispatch(ShellAction::CloseCommandPalette);
                         shell.add_panel_chooser_open = !shell.add_panel_chooser_open;
-                        window.focus(&shell.root_focus);
+                        window.focus(&shell.root_focus, cx);
                         cx.notify();
                     })),
             )
@@ -2622,8 +2626,8 @@ impl LumbridgeShell {
             .relative()
             .track_focus(&self.root_focus)
             .key_context("LumbridgeShell")
-            .on_click(cx.listener(|shell, _, window, _| {
+            .on_click(cx.listener(|shell, _, window, cx| {
-                window.focus(&shell.root_focus);
+                window.focus(&shell.root_focus, cx);
             }))
             .on_action(cx.listener(Self::focus_left))
             .on_action(cx.listener(Self::focus_right))
@@ -3429,7 +3433,7 @@ fn spawn_live_runtime(
 }
 
 fn main() {
-    Application::new().run(|cx: &mut App| {
+    application().run(|cx: &mut App| {
         cx.bind_keys(keymap::bindings());
 
         let bounds = Bounds::centered(None, size(px(1500.0), px(960.0)), cx);

apps/lumbridge/src/sidebar/view.rs

@@ -198,7 +198,7 @@ pub(crate) fn row(row: &SidebarRow, style: &RowStyle) -> gpui::AnyElement {
             // that says which pane to look at.
             .child(
                 div()
-                    .flex_shrink()
+                    .flex_shrink(1.0)
                     .min_w(px(0.0))
                     .truncate()
                     .text_xs()
@@ -261,7 +261,7 @@ pub(crate) fn row(row: &SidebarRow, style: &RowStyle) -> gpui::AnyElement {
             )
             .child(
                 div()
-                    .flex_shrink()
+                    .flex_shrink(1.0)
                     .min_w(px(0.0))
                     .truncate()
                     .text_xs()

scripts/workspace-guard.sh

@@ -49,30 +49,42 @@ done < <(find apps crates tools -mindepth 2 -maxdepth 2 -name Cargo.toml 2>/dev/
 #
 # Checked against Cargo.lock rather than the manifest, because the manifest
 # states an intent and the lockfile states what would actually be compiled --
-# and a caret requirement in the manifest silently accepts a version nobody
+# and a manifest `rev` can drift from the revision that was actually resolved,
+# just as the caret requirement it replaced silently accepted a version nobody
 # decided on. Asserted in the fast headless job so it gates every push, and not
 # in the UI job, which is `continue-on-error` and therefore cannot fail one.
 #
-# Changing this line means writing a decision record. See AGENTS.md,
+# Decision 0023 moved this from published crates.io 0.2.2 to a full-SHA
+# revision of Zed. Two packages arrive from it, and they must arrive from the
+# SAME revision: `gpui` is the framework, `gpui_platform` is the entry point and
+# the Linux backends that the publishable crate no longer contains. A pair that
+# disagreed would compile against two different framework snapshots. Their
+# `version` fields differ (0.2.2 and 0.1.0) and mean nothing here -- neither has
+# been bumped upstream in ten months -- so the revision is what is asserted.
+#
+# Changing these lines means writing a decision record. See AGENTS.md,
 # "Dependencies that are not an agent's decision".
-expected_gpui_source='registry+https://github.com/rust-lang/crates.io-index'
+expected_gpui_git='https://github.com/zed-industries/zed.git'
-expected_gpui_version='0.2.2'
+expected_gpui_rev='ce48461eaadd16c65c31f835511ab96bd3b6e746'
+expected_gpui_source="git+$expected_gpui_git?rev=$expected_gpui_rev#$expected_gpui_rev"
 
-gpui_block="$(awk '/^name = "gpui"$/{found=1} found{print} found&&/^$/{exit}' Cargo.lock)"
+for pkg in gpui gpui_platform; do
-if [ -z "$gpui_block" ]; then
+  block="$(awk -v pkg="$pkg" '$0 == "name = \"" pkg "\""{found=1} found{print} found&&/^$/{exit}' Cargo.lock)"
-  echo "workspace-guard: no gpui package in Cargo.lock; the shell cannot build." >&2
+  if [ -z "$block" ]; then
-  status=1
+    echo "workspace-guard: no $pkg package in Cargo.lock; the shell cannot build." >&2
-else
+    status=1
-  actual_version="$(printf '%s' "$gpui_block" | sed -n 's/^version = "\(.*\)"$/\1/p')"
+    continue
-  actual_source="$(printf '%s' "$gpui_block" | sed -n 's/^source = "\(.*\)"$/\1/p')"
+  fi
-  if [ "$actual_version" != "$expected_gpui_version" ] || [ "$actual_source" != "$expected_gpui_source" ]; then
+  actual_source="$(printf '%s' "$block" | sed -n 's/^source = "\(.*\)"$/\1/p')"
-    echo "workspace-guard: the gpui dependency is not the one the decision record chose." >&2
+  if [ "$actual_source" != "$expected_gpui_source" ]; then
-    echo "                 expected $expected_gpui_version from $expected_gpui_source" >&2
+    echo "workspace-guard: the $pkg dependency is not the one the decision record chose." >&2
-    echo "                 found    $actual_version from $actual_source" >&2
+    echo "                 expected $expected_gpui_source" >&2
+    echo "                 found    ${actual_source:-<no source: a path or workspace override>}" >&2
+    echo "                 Both gpui crates must carry rev $expected_gpui_rev." >&2
     echo "                 A bump is a decision record, not a commit. See AGENTS.md." >&2
     status=1
   fi
-fi
+done
 
 if [ "$status" = 0 ]; then
   echo "workspace-guard: crate membership and the pinned UI dependency are as recorded."