web-ext will not work when following the instructions without having
this diff applied:
```
$ ./node_modules/web-ext/bin/web-ext run -s src/
(node:41062) Warning: Accessing non-existent property 'cat' of module exports inside circular dependency
(Use `node --trace-warnings ...` to show where the warning was created)
(node:41062) Warning: Accessing non-existent property 'cd' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'chmod' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'cp' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'dirs' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'pushd' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'popd' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'echo' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'tempdir' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'pwd' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'exec' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'ls' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'find' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'grep' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'head' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'ln' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'mkdir' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'rm' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'mv' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'sed' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'set' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'sort' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'tail' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'test' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'to' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'toEnd' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'touch' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'uniq' of module exports inside circular dependency
(node:41062) Warning: Accessing non-existent property 'which' of module exports inside circular dependency
Applying config file: ./package.json
Running web extension from /home/andre/Git/multi-account-containers/src
Use --verbose or open Tools > Web Developer > Browser Console to see logging
WebExtError: Temporary add-on installation is not supported in this version of Firefox (you need Firefox 49 or higher). For older Firefox versions, use --pre-install
at FirefoxDesktopExtensionRunner._callee6$ (/home/andre/Git/multi-account-containers/node_modules/web-ext/dist/webpack:/src/extension-runners/firefox-desktop.js:273:19)
at tryCatch (/home/andre/Git/multi-account-containers/node_modules/web-ext/node_modules/regenerator-runtime/runtime.js:62:40)
at Generator.invoke [as _invoke] (/home/andre/Git/multi-account-containers/node_modules/web-ext/node_modules/regenerator-runtime/runtime.js:296:22)
at Generator.prototype.<computed> [as throw] (/home/andre/Git/multi-account-containers/node_modules/web-ext/node_modules/regenerator-runtime/runtime.js:114:21)
at step (/home/andre/Git/multi-account-containers/node_modules/web-ext/dist/webpack:/node_modules/babel-runtime/helpers/asyncToGenerator.js:17:1)
at /home/andre/Git/multi-account-containers/node_modules/web-ext/dist/webpack:/node_modules/babel-runtime/helpers/asyncToGenerator.js:30:1
at processTicksAndRejections (node:internal/process/task_queues:93:5)
```
web-ext will work when following the instructions with having this diff
applied:
```
$ web-ext run -s src/
Applying config file: ./package.json
Running web extension from /home/andre/Git/multi-account-containers/src
Use --verbose or open Tools > Web Developer > Browser Console to see logging
Installed /home/andre/Git/multi-account-containers/src as a temporary add-on
The extension will reload if any source file changes
Press R to reload (and Ctrl-C to quit)
```
I copied the wording from
2184fee75a/README.md
I guess the underlying problem is that the web-ext version specified in
the package.json is very outdated. By installing the web-ext tool via
the provided instructions it fixes the problem.
Furthermore, the `webextensions-examples` repo doesn't specify web-ext
in their package.json which means that installing web-ext via the
provided instructions seems to be the preferred way. (So maybe web-ext
should be removed from the package.json entirely?)
Fixes#1926
