Rails 6.1 command webpack not found when precompiling assets in capistrano

Question

I have a capistrano/sshkit problem with rake assets:precompile generating command webpack not found when my capistrano apply_theme task is invoked

I have the bin folder checked into source control and I have node version v12.18.1 and yarn version 1.22.4

    set :rvm_map_bins, [ 'rake', 'gem', 'bundle', 'ruby', 'puma', 'pumactl', 'webpack' ]
    
    namespace :deploy do
    
      desc 'Updating theme'
      task apply_theme: [:set_rails_env] do
        on roles(:app) do
          within release_path do
            with rails_env: fetch(:rails_env) do
              execute :rake, 'write_css'
              execute :rake, 'assets:precompile'
            end
          end
        end
      end
#etc...

This has worked previously prior to updating from rails 6.0.3.2 to 6.1 alpha

The following when run directly on the server works

RAILS_ENV="production" bundle exec rake assets:precompile

and generates

Compiling...
Compiled all packs in /home/comtechrcc/rawdoncc/releases/20200629090644/public/packs
Hash: b1c4524d882fd4ab2775
Version: webpack 4.43.0
Time: 6696ms
Built at: 06/30/2020 3:07:43 PM
                                             Asset       Size  Chunks                                Chunk Names
            js/application-e8c232440ca35fbfc7ed.js    164 KiB       0  [emitted] [immutable]         application
js/application-e8c232440ca35fbfc7ed.js.LICENSE.txt  497 bytes          [emitted]                     
         js/application-e8c232440ca35fbfc7ed.js.br   44.3 KiB          [emitted]                     
         js/application-e8c232440ca35fbfc7ed.js.gz   50.1 KiB          [emitted]                     
        js/application-e8c232440ca35fbfc7ed.js.map    674 KiB       0  [emitted] [dev]               application
     js/application-e8c232440ca35fbfc7ed.js.map.br    164 KiB          [emitted]                     
     js/application-e8c232440ca35fbfc7ed.js.map.gz    192 KiB          [emitted]                     
                js/consent-3541241bff4d08d2cdc8.js   1.74 KiB       1  [emitted] [immutable]         consent
             js/consent-3541241bff4d08d2cdc8.js.br  779 bytes          [emitted]                     
             js/consent-3541241bff4d08d2cdc8.js.gz  951 bytes          [emitted]                     
            js/consent-3541241bff4d08d2cdc8.js.map   6.12 KiB       1  [emitted] [dev]               consent
         js/consent-3541241bff4d08d2cdc8.js.map.br   2.12 KiB          [emitted]                     
         js/consent-3541241bff4d08d2cdc8.js.map.gz   2.45 KiB          [emitted]                     
                js/jscolor-fbb513be09d718775c40.js   29.1 KiB       2  [emitted] [immutable]         jscolor
    js/jscolor-fbb513be09d718775c40.js.LICENSE.txt  276 bytes          [emitted]                     
             js/jscolor-fbb513be09d718775c40.js.br   7.27 KiB          [emitted]                     
             js/jscolor-fbb513be09d718775c40.js.gz   8.19 KiB          [emitted]                     
            js/jscolor-fbb513be09d718775c40.js.map    102 KiB       2  [emitted] [dev]               jscolor
         js/jscolor-fbb513be09d718775c40.js.map.br   23.1 KiB          [emitted]                     
         js/jscolor-fbb513be09d718775c40.js.map.gz   26.9 KiB          [emitted]                     
               js/sortable-35a5ae5fe10b2c580832.js    395 KiB       3  [emitted] [immutable]  [big]  sortable
   js/sortable-35a5ae5fe10b2c580832.js.LICENSE.txt   5.18 KiB          [emitted]                     
            js/sortable-35a5ae5fe10b2c580832.js.br   94.7 KiB          [emitted]                     
            js/sortable-35a5ae5fe10b2c580832.js.gz    111 KiB          [emitted]                     
           js/sortable-35a5ae5fe10b2c580832.js.map   1.52 MiB       3  [emitted] [dev]               sortable
        js/sortable-35a5ae5fe10b2c580832.js.map.br    344 KiB          [emitted]              [big]  
        js/sortable-35a5ae5fe10b2c580832.js.map.gz    415 KiB          [emitted]              [big]  
             js/transition-819672c9d2985c533475.js   17.8 KiB       4  [emitted] [immutable]         transition
          js/transition-819672c9d2985c533475.js.br   4.21 KiB          [emitted]                     
          js/transition-819672c9d2985c533475.js.gz   4.73 KiB          [emitted]                     
         js/transition-819672c9d2985c533475.js.map   61.6 KiB       4  [emitted] [dev]               transition
      js/transition-819672c9d2985c533475.js.map.br   14.3 KiB          [emitted]                     
      js/transition-819672c9d2985c533475.js.map.gz   16.2 KiB          [emitted]                     
                                     manifest.json    1.6 KiB          [emitted]                     
                                  manifest.json.br  289 bytes          [emitted]                     
                                  manifest.json.gz  335 bytes          [emitted]                     
Entrypoint application = js/application-e8c232440ca35fbfc7ed.js js/application-e8c232440ca35fbfc7ed.js.map
Entrypoint consent = js/consent-3541241bff4d08d2cdc8.js js/consent-3541241bff4d08d2cdc8.js.map
Entrypoint jscolor = js/jscolor-fbb513be09d718775c40.js js/jscolor-fbb513be09d718775c40.js.map
Entrypoint sortable [big] = js/sortable-35a5ae5fe10b2c580832.js js/sortable-35a5ae5fe10b2c580832.js.map
Entrypoint transition = js/transition-819672c9d2985c533475.js js/transition-819672c9d2985c533475.js.map
 [1] (webpack)/buildin/module.js 552 bytes {0} {3} [built]
 [8] ./app/javascript/packs/application.js 790 bytes {0} [built]
[12] ./app/javascript/channels/index.js 205 bytes {0} [built]
[13] ./app/javascript/channels sync _channel\.js$ 160 bytes {0} [built]
[14] ./app/javascript/packs/consent.js 835 bytes {1} [built]
[15] ./app/javascript/packs/jscolor.js 42.7 KiB {2} [built]
[16] ./app/javascript/packs/sortable.js 1.35 KiB {3} [built]
[29] ./app/javascript/packs/transition.js 43 bytes {4} [built]
    + 42 hidden modules

WARNING in asset size limit: The following asset(s) exceed the recommended size limit (244 KiB).
This can impact web performance.
Assets: 
  js/sortable-35a5ae5fe10b2c580832.js (395 KiB)
  js/sortable-35a5ae5fe10b2c580832.js.map.gz (415 KiB)
  js/sortable-35a5ae5fe10b2c580832.js.map.br (344 KiB)

WARNING in entrypoint size limit: The following entrypoint(s) combined asset size exceeds the recommended limit (244 KiB). This can impact web performance.
Entrypoints:
  sortable (395 KiB)
      js/sortable-35a5ae5fe10b2c580832.js


WARNING in webpack performance recommendations: 
You can limit the size of your bundles by using import() or require.ensure to lazy load some parts of your application.
For more info visit https://webpack.js.org/guides/code-splitting/

However when running cap production deploy from my dev box I get error command webpack not found

Tasks: TOP => deploy:publishing => deploy:apply_theme
(See full trace by running task with --trace)
The deploy has failed with an error: Exception while executing on host 46.101.0.71: rake exit status: 1
rake stdout: I, [2020-07-01T03:47:22.236597 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/manifest-2f0ac84ec540eb753a59078be1e78cb9bb00e12a9a8d6d826039a818a0008610.js
I, [2020-07-01T03:47:22.237088 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/manifest-2f0ac84ec540eb753a59078be1e78cb9bb00e12a9a8d6d826039a818a0008610.js.gz
I, [2020-07-01T03:47:22.237444 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/favicon-f4118a1c7993795f1519263cb07b5a52f770bd479e7a3b7b34a208f42fafeb61.ico
I, [2020-07-01T03:47:22.237828 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/favicon-f4118a1c7993795f1519263cb07b5a52f770bd479e7a3b7b34a208f42fafeb61.ico.gz
I, [2020-07-01T03:47:22.241489 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/site_banner-033c28f13b6778452c5dd702a065af245ed31642327ce5b2280d9640cf089bf6.wbp
I, [2020-07-01T03:47:22.242715 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/_admin_form-95a7cf026326d501435d2fc694548a5b58d8647f9f0615c50518337467088212.css
I, [2020-07-01T03:47:22.243303 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/_admin_form-95a7cf026326d501435d2fc694548a5b58d8647f9f0615c50518337467088212.css.gz
I, [2020-07-01T03:47:22.243805 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/_colours-04024382391bb910584145d8113cf35ef376b55d125bb4516cebeb14ce788597.css
I, [2020-07-01T03:47:22.244406 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/_colours-04024382391bb910584145d8113cf35ef376b55d125bb4516cebeb14ce788597.css.gz
I, [2020-07-01T03:47:22.244884 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/_desktop_menu-6e52e9314b9a7eaef17cad3136965fb213c3ec8fa8047cb7b3cfc37f7ea7ea89.css
I, [2020-07-01T03:47:22.245398 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/_desktop_menu-6e52e9314b9a7eaef17cad3136965fb213c3ec8fa8047cb7b3cfc37f7ea7ea89.css.gz
I, [2020-07-01T03:47:22.245968 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/_hamburger-33ded8e64b166a1bcc8737964605b5e46d831806b68dfc94c5140e7dfc68b425.css
I, [2020-07-01T03:47:22.246777 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/_hamburger-33ded8e64b166a1bcc8737964605b5e46d831806b68dfc94c5140e7dfc68b425.css.gz
I, [2020-07-01T03:47:22.247827 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/_transitions-8de27d1347ed98a4ca72069157aa301736c2d0500d69ac46e10f34585af52feb.css
I, [2020-07-01T03:47:22.248421 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/_transitions-8de27d1347ed98a4ca72069157aa301736c2d0500d69ac46e10f34585af52feb.css.gz
I, [2020-07-01T03:47:22.249046 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/admin-eaa1632cb988456192ab0be1d1bc4a46a9fa35645dbb20d3f7b603500dcfacf4.css
I, [2020-07-01T03:47:22.249989 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/admin-eaa1632cb988456192ab0be1d1bc4a46a9fa35645dbb20d3f7b603500dcfacf4.css.gz
I, [2020-07-01T03:47:22.250635 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/admin_menu-a1563e06176e5fb2d653672395ac99b0318adfb2258067d5383ec149e3863110.css
I, [2020-07-01T03:47:22.251841 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/admin_menu-a1563e06176e5fb2d653672395ac99b0318adfb2258067d5383ec149e3863110.css.gz
I, [2020-07-01T03:47:22.252193 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/application-6b209f68260d4aa8838da9700b91b9f025959195a3c0696822be06f3d8e6f009.css
I, [2020-07-01T03:47:22.252566 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/application-6b209f68260d4aa8838da9700b91b9f025959195a3c0696822be06f3d8e6f009.css.gz
I, [2020-07-01T03:47:22.253181 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/config_settings-04024382391bb910584145d8113cf35ef376b55d125bb4516cebeb14ce788597.css
I, [2020-07-01T03:47:22.254898 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/config_settings-04024382391bb910584145d8113cf35ef376b55d125bb4516cebeb14ce788597.css.gz
I, [2020-07-01T03:47:22.255359 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/contact-04024382391bb910584145d8113cf35ef376b55d125bb4516cebeb14ce788597.css
I, [2020-07-01T03:47:22.256155 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/contact-04024382391bb910584145d8113cf35ef376b55d125bb4516cebeb14ce788597.css.gz
I, [2020-07-01T03:47:22.256568 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/pages-9c1dbf39f3ef6ef34622882460a0f51f6eb58a6201713590b6a5190ae5b1274d.css
I, [2020-07-01T03:47:22.257460 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/pages-9c1dbf39f3ef6ef34622882460a0f51f6eb58a6201713590b6a5190ae5b1274d.css.gz
I, [2020-07-01T03:47:22.258114 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/public-c5142a4f07440ec9943b8844c852f347acb7efcb4e1c1e20f4bf779c64094957.css
I, [2020-07-01T03:47:22.258819 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/public-c5142a4f07440ec9943b8844c852f347acb7efcb4e1c1e20f4bf779c64094957.css.gz
I, [2020-07-01T03:47:22.259434 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/public_menu-8368c148d0882cf2768aa2622f8d0300dc746c8e3846301d0a5a4f422dfe0c60.css
I, [2020-07-01T03:47:22.260123 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/public_menu-8368c148d0882cf2768aa2622f8d0300dc746c8e3846301d0a5a4f422dfe0c60.css.gz
I, [2020-07-01T03:47:22.260809 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/scaffolds-8abf05aa587d598a9a5f19e75f4e131f166c0ce16b233bdc5e251a167ac0b1e1.css
I, [2020-07-01T03:47:22.261687 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/scaffolds-8abf05aa587d598a9a5f19e75f4e131f166c0ce16b233bdc5e251a167ac0b1e1.css.gz
I, [2020-07-01T03:47:22.262092 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/app-7c3c38da788947165eb5b3f5bbec4f13416145f32b2fcc8835e2718a332f537b.js
I, [2020-07-01T03:47:22.262438 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/app-7c3c38da788947165eb5b3f5bbec4f13416145f32b2fcc8835e2718a332f537b.js.gz
I, [2020-07-01T03:47:22.263908 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/new_ckeditor/classic/ckeditor-f35d4f83a73c0f0e7fb53ceaf4c0443d00eb0fc917b0cdd5ab8230635503131e.js
I, [2020-07-01T03:47:22.264229 #101477]  INFO -- : Writing /home/comtechrcc/rawdoncc/releases/20200701034704/public/assets/new_ckeditor/classic/ckeditor-f35d4f83a73c0f0e7fb53ceaf4c0443d00eb0fc917b0cdd5ab8230635503131e.js.gz
Compiling...
Compilation failed:
yarn run v1.22.4
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.


error Command "webpack" not found.

Answer 1

run the following command:

yarn add webpack

this should fix the issue

Answer 2

Found the solution here (thx Michael for putting it out there).

The problem is not related to the "webpack" dependency, you just need a binstub in your bin folder

Create a file purely called yarn and add these lines.

#!/usr/bin/env ruby
APP_ROOT = File.expand_path('..', __dir__)
Dir.chdir(APP_ROOT) do
  begin
    exec "yarnpkg", *ARGV
  rescue Errno::ENOENT
    $stderr.puts "Yarn executable was not detected in the system."
    $stderr.puts "Download Yarn at https://yarnpkg.com/en/docs/install"
    exit 1
  end
end

Then make it executable. Switch to the bin folder and enter this in the console

chmod +x yarn

That worked for me!