From c61e93a1f3f6aa5d0f09904c685cd51db0762f4b Mon Sep 17 00:00:00 2001
From: Kit Langton <kit.langton@gmail.com>
Date: Tue, 7 Jul 2026 22:11:14 -0400
Subject: [PATCH] fix(cli): harden election edge cases

---
 packages/cli/src/server-process.ts     |  8 ++++++--
 packages/core/src/util/effect-flock.ts | 11 ++++++-----
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/packages/cli/src/server-process.ts b/packages/cli/src/server-process.ts
index c0ab18d2d2..6ed14cba6e 100644
--- a/packages/cli/src/server-process.ts
+++ b/packages/cli/src/server-process.ts
@@ -29,7 +29,7 @@ type ManagedServiceOptions = Service.Options & { readonly file: string }
 
 export const run = Effect.fn("cli.server-process.run")((options: Options) =>
   processEffect(options).pipe(
-    Effect.catchTag("ServiceAlreadyOwned", () => Effect.void),
+    Effect.catchTag("ServiceAlreadyOwned", () => Effect.logInfo("another process owns the managed service, exiting")),
     Effect.provide(Updater.layer),
     Effect.provide(AppNodeBuilder.build(LayerNode.group([Global.node, AppProcess.node, EffectFlock.node]))),
     Effect.provide(NodeServices.layer),
@@ -55,7 +55,11 @@ const processEffect = Effect.fnUntraced(function* (options: Options) {
             (acquired) => acquired,
             () => ({ _tag: "ServiceAlreadyOwned" }) as const,
           ),
-          Effect.retry(Schedule.spaced("100 millis").pipe(Schedule.both(Schedule.recurs(20)))),
+          // Retry only lost elections: a displaced owner may take a moment to release.
+          Effect.retry({
+            while: (error) => error._tag === "ServiceAlreadyOwned",
+            schedule: Schedule.spaced("100 millis").pipe(Schedule.both(Schedule.recurs(20))),
+          }),
         )
       }
       const password =
diff --git a/packages/core/src/util/effect-flock.ts b/packages/core/src/util/effect-flock.ts
index a3f70719b9..bd9e1c5e2a 100644
--- a/packages/core/src/util/effect-flock.ts
+++ b/packages/core/src/util/effect-flock.ts
@@ -164,11 +164,12 @@ export namespace EffectFlock {
               process.kill(owner.pid, 0)
               return true
             },
-            catch: (cause) => {
-              const code = cause && typeof cause === "object" && "code" in cause ? cause.code : undefined
-              return code !== "ESRCH"
-            },
-          }).pipe(Effect.orElseSucceed(() => false))
+            catch: (cause) => (cause && typeof cause === "object" && "code" in cause ? cause.code : undefined),
+          }).pipe(
+            // Only ESRCH proves the pid is gone; other errors (e.g. EPERM) mean a
+            // process exists, so never break a possibly live owner's lock.
+            Effect.catch((code) => Effect.succeed(code !== "ESRCH")),
+          )
           if (!alive) return true
         }