Gyazo Crostiniが動かなくなった件の調査 2021/8
結論
ChromeOS標準のスクリーンショット機能の保存先は、常に「ダウンロード」フォルダになった
Linux側からスクショ画像の生成を検知する術がなくなった？
現時点ではGyazo Crostiniの修正方法は思いつかない 
Chromebookを使わなくなってきた
問題
Pixel SlateでGyazo Crostiniが動かなくなった
ChromeOSでスクリーンショットの保存場所として「Linux ファイル」内のフォルダを選んでも無視されるようになった？
OS標準のスクリーンショットの保存先が問答無用で「ダウンロード」フォルダになったようだ
これまでは自分で指定した「Linux ファイル > CrDownloads」フォルダに保存できていた
OS情報
92.0.4515.130 (Official Build) (64ビット)
Chromium OSの関連コードを眺めてみる
なるほどわからん
Redditで仲間を見つけた
Before Chrome OS 90, my screenshots were automatically saved in my screenshots folder, but with the new update it no longer does that, even though the downloads are set to a screenshot folder in advanced settings.
これに対するレス
I have opened a bug report about this.
Please go to that report and shar it to show your interest. Also, add your experience about how it worked before and why you set up your Chromebook that way. Like you, I wanted to keep screenshots from clogging up the folder where I save other downloads.
Issue
2. Take screenshots or download something
3. The screenshots and files appear in the original ChromeOS "Downloads" folder, not the new folder
4. Click on the Chrome 3-dot menu and select the "Downloads" option. The default Downloads folder content is displayed, not the contents of the new downloads folder.
WontFixとのこと
Thank you for your thoughtful feedback! Yes, exactly. We'll add a new "save to" feature in the tool's settings itself.
In summary, the "Downloads" folder is a Chrome browser setting. Screen Capture is an OS feature that shouldn't rely on an app setting. We received a ton of feedback of this setting breaking the feature (for ex: users setting their downloads folder to an invalid location, or a USB stick that is no longer connected).
We will keep you posted on progress and appreciate your patience as we make sure this feature works for everyone.