Atom.Object.defineProperty.get is deprecated.

[varemenos]

atom.workspaceView is no longer available.
In most cases you will not need the view. See the Workspace docs for
alternatives: https://atom.io/docs/api/latest/Workspace.
If you do need the view, please use atom.views.getView(atom.workspace),
which returns an HTMLElement.

Atom.Object.defineProperty.get (/opt/homebrew-cask/Caskroom/atom/latest/Atom.app/Contents/Resources/app.asar/src/atom.js:57:13)
atom-workspace.atom.commands.add.pane:show-next-item (/Users/akakoulidis/.atom/packages/synced-sidebar/lib/synced-sidebar.coffee:20:11)
CommandRegistry.module.exports.CommandRegistry.handleCommandEvent (/opt/homebrew-cask/Caskroom/atom/latest/Atom.app/Contents/Resources/app.asar/src/command-registry.js:238:29)
<unknown> (/opt/homebrew-cask/Caskroom/atom/latest/Atom.app/Contents/Resources/app.asar/src/command-registry.js:3:61)
KeymapManager.dispatchCommandEvent (/opt/homebrew-cask/Caskroom/atom/latest/Atom.app/Contents/Resources/app.asar/node_modules/atom-keymap/lib/keymap-manager.js:519:16)
KeymapManager.handleKeyboardEvent (/opt/homebrew-cask/Caskroom/atom/latest/Atom.app/Contents/Resources/app.asar/node_modules/atom-keymap/lib/keymap-manager.js:354:22)

[peterdotjs]

Fixed in 8063f89 but currently having issues with apm publish.

[peterdotjs]

Resolved in v0.4.