preact watch fails with emacs lock files / dead symbolic links

[mguentner]

Do you want to request a feature or report a bug?

bug

What is the current behaviour?

• $ preact watch
• I can access 127.0.0.1:8080 and use the application :heavy_check_mark:
• After changing a file "file.xyz" in my editor (emacs), a state file is created: ".#file.xyz"
• the preact process crashes:

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! [email protected] start:development: `npm run -s dev`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the [email protected] start:development script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/user/.npm/_logs/2020-05-24T17_29_55_141Z-debug.log
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

Extract from npm error log:

10 verbose lifecycle [email protected]~start:development: CWD: /home/user/code/project
11 silly lifecycle [email protected]~start:development: Args: [ '-c', 'npm run -s dev' ]
12 silly lifecycle [email protected]~start:development: Returned: code: 1  signal: null
13 info lifecycle [email protected]~start:development: Failed to exec start:development script
14 verbose stack Error: [email protected] start:development: `npm run -s dev`
14 verbose stack Exit status 1
14 verbose stack     at EventEmitter.<anonymous> (/usr/lib/node_modules/npm/node_modules/npm-lifecycle/index.js:332:16)
14 verbose stack     at EventEmitter.emit (events.js:315:20)
14 verbose stack     at ChildProcess.<anonymous> (/usr/lib/node_modules/npm/node_modules/npm-lifecycle/lib/spawn.js:55:14)
14 verbose stack     at ChildProcess.emit (events.js:315:20)
14 verbose stack     at maybeClose (internal/child_process.js:1051:16)
14 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:287:5)
15 verbose pkgid [email protected]
16 verbose cwd /home/user/code/project
17 verbose Linux 5.6.11-arch1-1
18 verbose argv "/usr/bin/node" "/usr/bin/npm" "run" "start:development"
19 verbose node v14.3.0
20 verbose npm  v6.14.5
21 error code ELIFECYCLE
22 error errno 1

Please paste the results of preact info here.

Environment Info:
  System:
    OS: Linux 5.6 Arch Linux
    CPU: (4) x64 Intel(R) Core(TM) i7-8565U CPU @ 1.80GHz
  Binaries:
    Node: 14.3.0 - /usr/bin/node
    Yarn: 1.22.4 - /usr/bin/yarn
    npm: 6.14.5 - /usr/bin/npm
  Browsers:
    Firefox: 76.0.1
  npmPackages:
    preact: ^10.4.4 => 10.4.4 
    preact-cli: ^3.0.0-rc.10 => 3.0.0-rc.10 
    preact-render-to-string: ^5.1.4 => 5.1.8 
    preact-router: ^3.2.1 => 3.2.1 
  npmGlobalPackages:
    preact-cli: 3.0.0-rc.10

** Note ** This happend after upgrading from 2.? to 3.0.0.

[mguentner]

I used $ inotifywait -r -m . to watch for file changes to see what is going on:

./ CREATE .#index.tsx
./ OPEN,ISDIR 
./ ACCESS,ISDIR 
./ CLOSE_NOWRITE,CLOSE,ISDIR 
./ OPEN,ISDIR 
./ ACCESS,ISDIR 
./ CLOSE_NOWRITE,CLOSE,ISDIR 

The .#index.tsx is a lock file: https://www.gnu.org/software/emacs/manual/html_node/elisp/File-Locks.html This points to [email protected]:boot which cannot resolved obviously.

With preact watch running you can emulate the behavior of emacs by creating a dead symlink:

ln -s does_not_exist foo

You should see a message like

✖ ERROR Error: ENOENT: no such file or directory, stat 'foo'

[mguentner]

:point_right: As a short-term solution, you can set create-lockfiles to nil in emacs to prevent preact watch from crashing

[zalox]

This was introduced upstream somewhere in this diff https://github.com/webpack/watchpack/compare/v1.6.1...v1.7.2

[zalox]

I encountered the same bug and manually selected version 1.6.1 in my package-lock.json file and was able to move on with my day.

Here is the entry for watchpack 1.6.1.

"watchpack": {
  "version": "1.6.1",
  "resolved": "https://registry.npmjs.org/watchpack/-/watchpack-1.6.1.tgz",
  "integrity": "sha512-+IF9hfUFOrYOOaKyfaI7h7dquUIOgyEMoQMLA7OP5FxegKA2+XdXThAZ9TU2kucfhDH7rfMHs1oPYziVGWRnZA==",
   "dev": true,
  "requires": {
    "chokidar": "^2.1.8",
   "graceful-fs": "^4.1.2",
   "neo-async": "^2.5.0"
 }
}
`

[mguentner]

If you use yarn, you can also add this to package.json:

  "resolutions": {
    "watchpack": "1.6.1"
  },

[developit]

Does this still happen in the 3.0.0 release?

[mguentner]

@developit the problem still happens with preact, 3.0.3