fix(cli): handle consecutive npx install race condition (#4643)

fern-api · Sep 14, 2024 · d73bf9c · d73bf9c
1 parent acb1e58
commit d73bf9c
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Showing 2 changed files with 17 additions and 1 deletion.
diff --git a/packages/cli/cli/src/rerunFernCliAtVersion.ts b/packages/cli/cli/src/rerunFernCliAtVersion.ts
@@ -27,14 +27,21 @@ export async function rerunFernCliAtVersion({
         ].join("\n")
     );
 
-    const { failed } = await loggingExeca(cliContext.logger, "npx", ["--quiet", ...commandLineArgs], {
+    const { failed, stdout, stderr } = await loggingExeca(cliContext.logger, "npx", ["--quiet", ...commandLineArgs], {
         stdio: "inherit",
         reject: false,
         env: {
             ...env,
             [FERN_CWD_ENV_VAR]: process.env[FERN_CWD_ENV_VAR] ?? process.cwd()
         }
     });
+    if (stdout.includes("code EEXIST") || stderr.includes("code EEXIST")) {
+        // try again if there is a npx conflict
+        return await rerunFernCliAtVersion({
+            version,
+            cliContext
+        });
+    }
 
     if (failed) {
         cliContext.failWithoutThrowing();

diff --git a/packages/cli/cli/versions.yml b/packages/cli/cli/versions.yml
@@ -1,3 +1,12 @@
+- changelogEntry:
+  - summary: |
+      The Fern CLI now safely handles a npx file exists error by retrying the command on failure. 
+      This error typically happens when two or more instances of the Fern CLI are running `npx`
+      at the same time. 
+    type: fix
+  irVersion: 53
+  version: 0.41.14-rc0
+
 - changelogEntry:
   - summary: |
       `fern generate --local` no longer crashes on large API Definitions because we