macOS "failed to find chromium executable"

[beefstew]

I just downloaded and built a copy of Sharedown but receive an error message while trying to download a SharePoint link: "failed to find chromium executable"

Sample URL: https://censored.sharepoint.com/:v:/r/personal/censored_com/Documents/Recordings/filename_Meeting%20Recording.mp4?csf=1&web=1&nav=eyJyZWZlcnJhbEluZm8iOnsicmVmZXJyYWxBcHAiOiJPbmVEcml2ZUZvckJ1c2luZXNzIiwicmVmZXJyYWxBcHBQbGF0Zm9ybSI6IldlYiIsInJlZmVycmFsTW9kZSI6InZpZXciLCJyZWZlcnJhbFZpZXciOiJNeUZpbGVzTGlua0NvcHkifX0&e=d56sZC

I think the issue is due to my lack of a code signing certificate and macOS is blocking access to the chromium executable. I had a similar issue with the manually-installed yt-dlp (file present in PATH, but error message stating it wasn't; had to allowlist the file via macOS System Settings).

From build logs, I can see:

yarn run v1.22.22
$ electron-builder
  • electron-builder  version=26.0.6 os=24.2.0
  • loaded configuration  file=package.json ("build" field)
  • writing effective config  file=dist/builder-effective-config.yaml
Downloading chrome 131.0.6778.108 - 153.9 MB [====================] 100% 0.0s 
chrome (131.0.6778.108) downloaded to /Users/chorn/Documents/src/Sharedown/node_modules/puppeteer/chrome/mac_arm-131.0.6778.108
Downloading chrome-headless-shell 131.0.6778.108 - 88.1 MB [====================] 100% 0.0s 
chrome-headless-shell (131.0.6778.108) downloaded to /Users/chorn/Documents/src/Sharedown/node_modules/puppeteer/chrome-headless-shell/mac_arm-131.0.6778.108
  • executing @electron/rebuild  electronVersion=33.4.0 arch=arm64 buildFromSource=false appDir=./
  • installing native dependencies  arch=arm64
  • preparing       moduleName=keytar arch=arm64
  • finished        moduleName=keytar arch=arm64
  • completed installing native dependencies
  • packaging       platform=darwin arch=arm64 electron=33.4.0 appOutDir=dist/mac-arm64
  • downloading     url=https://github.com/electron/electron/releases/download/v33.4.0/electron-v33.4.0-darwin-arm64.zip size=100 MB parts=8
  • downloaded      url=https://github.com/electron/electron/releases/download/v33.4.0/electron-v33.4.0-darwin-arm64.zip duration=3.532s
  • skipped macOS application code signing  reason=cannot find valid "Developer ID Application" identity or custom non-Apple code signing certificate