Our laravel 8/vuejs 2 app at some moment raised critical error :
 UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by
In the project several developers work under ubuntu/windows and at my side(ubuntu) running commands: npm install npm audit fix and $ npm run watch-poll I got some warnings/errors:
serge@AtHome:/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded$ npm install
up to date, audited 875 packages in 3s
86 packages are looking for funding
  run `npm fund` for details
8 vulnerabilities (5 high, 3 critical)
To address issues that do not require attention, run:
  npm audit fix
To address all issues possible (including breaking changes), run:
  npm audit fix --force
Some issues need review, and may require choosing
a different dependency.
Run `npm audit` for details.
serge@AtHome:/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded$ npm audit fix
up to date, audited 875 packages in 2s
86 packages are looking for funding
  run `npm fund` for details
# npm audit report
axios  <0.21.1
Severity: high
Server-Side Request Forgery - https://npmjs.com/advisories/1594
No fix available
node_modules/vue-upload-multiple-image/node_modules/axios
  vue-upload-multiple-image  *
  Depends on vulnerable versions of axios
  node_modules/vue-upload-multiple-image
object-path  < 0.11.5
Severity: high
Prototype Pollution - https://npmjs.com/advisories/1573
fix available via `npm audit fix --force`
Will install resolve-url-loader@4.0.0, which is a breaking change
node_modules/object-path
  adjust-sourcemap-loader  0.1.0 - 2.0.0
  Depends on vulnerable versions of object-path
  node_modules/adjust-sourcemap-loader
    resolve-url-loader  0.0.1-experiment-postcss || 2.0.0 - 3.1.1 || 4.0.0-alpha.1 - 4.0.0-beta.2
    Depends on vulnerable versions of adjust-sourcemap-loader
    node_modules/resolve-url-loader
swiper  <6.5.1
Severity: critical
Prototype Pollution - https://npmjs.com/advisories/1694
fix available via `npm audit fix`
node_modules/swiper
  vue-awesome-swiper  *
  Depends on vulnerable versions of swiper
  node_modules/vue-awesome-swiper
    vue-image-lightbox-carousel  *
    Depends on vulnerable versions of vue-awesome-swiper
    node_modules/vue-image-lightbox-carousel
8 vulnerabilities (5 high, 3 critical)
To address issues that do not require attention, run:
  npm audit fix
To address all issues possible (including breaking changes), run:
  npm audit fix --force
Some issues need review, and may require choosing
a different dependency.
serge@AtHome:/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded$ npm run watch-poll
> watch-poll
> mix watch -- --watch-options-poll=1000
● Mix █████████████████████████ emitting (98%)
 after emit
: Using / for division is deprecated and will be removed in Dart Sass 2.0.0.
Recommendation: math.div(1, $rfs-rem-value)
More info and automated migrator: https://sass-lang.com/d/slash-div
   ╷
51 │   $rfs-base-font-size: math.div($rfs-base-font-size, $rfs-base-font-size * 0 + 1 / $rfs-rem-value);
   │                                                                                ^^^^^^^^^^^^^^^^^^
   ╵
    node_modules/bootstrap/scss/vendor/_rfs.scss 51:80  @import
    node_modules/bootstrap/scss/_mixins.scss 6:9        @import
    node_modules/bootstrap/scss/bootstrap.scss 10:9     @import
    stdin 5:9                                           root stylesheet
: Using / for division is deprecated and will be removed in Dart Sass 2.0.0.
Recommendation: math.div(1, $rfs-rem-value)
More info and automated migrator: https://sass-lang.com/d/slash-div
   ╷
87 │       $fs: math.div($fs, $fs * 0 + 1 / $rfs-rem-value);
   │                                    ^^^^^^^^^^^^^^^^^^
   ╵
    node_modules/bootstrap/scss/vendor/_rfs.scss 87:36  rfs()
    node_modules/bootstrap/scss/vendor/_rfs.scss 201:3  font-size()
    node_modules/bootstrap/scss/_reboot.scss 49:3       @import
    node_modules/bootstrap/scss/bootstrap.scss 12:9     @import
    stdin 5:9                                           root stylesheet
: math.div() will only support number arguments in a future release.
Use list.slash() instead for a slash separator.
    ╷
120 │         background: $custom-select-background, $custom-select-bg escape-svg($icon) math.div($custom-select-feedback-icon-position, $custom-select-feedback-icon-size) no-repeat;
    │                                                                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    ╵
    node_modules/bootstrap/scss/mixins/_forms.scss 120:84  @content
    node_modules/bootstrap/scss/mixins/_forms.scss 37:7    form-validation-state-selector()
    node_modules/bootstrap/scss/mixins/_forms.scss 115:5   form-validation-state()
    node_modules/bootstrap/scss/_forms.scss 263:3          @import
    node_modules/bootstrap/scss/bootstrap.scss 18:9        @import
    stdin 5:9                                              root stylesheet
(node:25343) UnhandledPromiseRejectionWarning: Error: ENOENT: no such file or directory, lstat '/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/vendor/proengsoft/laravel-jsvalidation/resources/views'
    at Object.lstatSync (fs.js:1077:3)
    at Object.lstatSync (/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/node_modules/graceful-fs/polyfills.js:311:34)
    at statFunc (/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/node_modules/fs-extra/lib/util/stat.js:24:20)
    at getStatsSync (/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/node_modules/fs-extra/lib/util/stat.js:25:19)
    at Object.checkPathsSync (/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/node_modules/fs-extra/lib/util/stat.js:67:33)
    at Object.copySync (/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/node_modules/fs-extra/lib/copy-sync/copy-sync.js:24:38)
    at File.copyTo (/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/node_modules/laravel-mix/src/File.js:245:12)
    at FileCollection.copyTo (/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/node_modules/laravel-mix/src/FileCollection.js:83:17)
    at /mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/node_modules/laravel-mix/src/FileCollection.js:77:38
    at Array.forEach (<anonymous>)
    at FileCollection.copyTo (/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/node_modules/laravel-mix/src/FileCollection.js:77:17)
    at CopyFilesTask.run (/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/node_modules/laravel-mix/src/tasks/CopyFilesTask.js:16:20)
    at CustomTasksPlugin.runTask (/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/node_modules/laravel-mix/src/webpackPlugins/CustomTasksPlugin.js:46:36)
    at CustomTasksPlugin.runTasks (/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/node_modules/laravel-mix/src/webpackPlugins/CustomTasksPlugin.js:87:21)
    at /mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/node_modules/laravel-mix/src/webpackPlugins/CustomTasksPlugin.js:20:18
    at Hook.eval [as callAsync] (eval at create (/mnt/_work_sdb8/wwwroot/lar/StreamgeeksRebrandedApp/streamgeeks-rebranded/node_modules/tapable/lib/HookCodeFactory.js:33:10), <anonymous>:73:1)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:25343) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 2)
Critical Error at the end is described at What is an unhandled promise rejection? but I failed to find source of this error. Please any hints how this error could be located and fixed?
$ node -v
v14.16.0
$ npm -v
7.19.0
$ uname -a
Linux AtHome 4.15.0-128-generic #131-Ubuntu SMP Wed Dec 9 06:57:35 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
Thanks!
