Failed to load the css-edit-groups package

[Enter steps to reproduce:]

1. ...
2. ...

Atom: 1.48.0 x64
Electron: 5.0.13
OS: DESKTOP-4S8CAG5
Thrown From: css-edit-groups package 0.4.2

Stack Trace

Failed to load the css-edit-groups package

At Duplicate key 'cmd-l'

Error: Duplicate key 'cmd-l'
    at Object.r (<embedded>:11:583069)
    at addProperty (<embedded>:14:1352180)
    at Array.reduce (<anonymous>:null:null)
    at Obj (<embedded>:14:1351846)
    at transformNode (<embedded>:14:1353220)
    at Value (<embedded>:14:1351094)
    at transformNode (<embedded>:14:1353220)
    at addProperty (<embedded>:14:1352168)
    at Array.reduce (<anonymous>:null:null)
    at Obj (<embedded>:14:1351846)
    at transformNode (<embedded>:14:1353220)
    at Value (<embedded>:14:1351094)
    at transformNode (<embedded>:14:1353220)
    at Block (<embedded>:14:1351052)
    at transformNode (<embedded>:14:1353220)
    at Object.parse (<embedded>:14:1353241)
    at m (<embedded>:11:580312)
    at c (<embedded>:11:580518)
    at Object.readFileSync (<embedded>:11:581611)
    at <embedded>:11:3301120
    at Array.map (<anonymous>:null:null)
    at Package.loadKeymaps (<embedded>:11:3301108)
    at <embedded>:11:3294562
    at Package.measure (<embedded>:11:3293757)
    at Package.load (<embedded>:11:3294498)
    at PackageManager.loadAvailablePackage (<embedded>:11:381522)
    at <embedded>:11:379945
    at Config.transact (<embedded>:11:332010)
    at PackageManager.loadPackages (<embedded>:11:379883)
    at <embedded>:1:755624
    at Function.all (<anonymous>:null:null)
    at AtomEnvironment.startEditorWindow (<embedded>:1:757663)

Commands

Non-Core Packages

atom-beautify 0.33.4 
atom-css-clean 2.24.1 
atom-html-preview 0.2.6 
atom-ternjs 0.20.0 
autoclose-html 0.23.0 
busy-signal 2.0.1 
css-color-name 0.4.0 
css-edit-groups 0.4.2 
css-spy 0.6.0 
csslint 1.2.0 
emmet 2.4.3 
emmet-jsx-css-modules 1.0.0 
html-to-css 0.2.2 
ide-css 0.3.4 
intentions 1.1.5 
language-ejs 0.4.0 
linter 2.3.1 
linter-eslint 8.5.5 
linter-ui-default 1.8.1 
pigments 0.40.2 
Sublime-Style-Column-Selection 1.7.5 

Reproduce the failure with Atom 1.48.0 and css-edit-groups 0.4.2, then inspect the package's keymap configuration because loading stops in Package.loadKeymaps. Identify the duplicate "cmd-l" entry and verify that the package loads without the duplicate-key error.