Tahoe 26.1 breaks Eclipse development environment

[svenmany]

Hello all,

This is just a heads-up if there happens to be any Eclipse developers on these forums.

I decided to upgrade to Tahoe on Sunday. On Monday I could not do any development in Eclipse due to an issue reported in these two places.

Cannot select multiple lines of text in Eclipse 2025-09 on macOS Tahoe 26.1 · Issue #2244 · eclipse-platform/eclipse.platform

After updating to macOS Tahoe 26.1, text selection in Eclipse 2025-09 (Build 4.37.0.20250905-1455) stopped working properly. Mouse drag does not select multiple lines. Shift + Arrow keys do not exp...

github.com

[macOS 26.1] Multiline selection highlighing is visually broken · Issue #2621 · eclipse-platform/eclipse.platform.swt

Describe the bug On Eclipse 2025-06 M3 (4.36.0 M3), the select all (command + A) is not working, even cursor selection also not working on any source code (java, docker, bash etc). The OS is MacOS ...

github.com

I was able to patch my own Eclipse, but that might not be available to all Eclipse users who are not free to apply updates or change releases.

The bug makes it impossible to see multi-line selections. The selections are made (evidenced by copy/paste), but there is no visible indication of the content being selected.

I did a fresh install of the latest Eclipse using the installer found at https://www.eclipse.org/downloads/. This delivered 2025-09 release. Then, following the instructions in the github issue, I added https://download.eclipse.org/eclipse/updates/4.38-I-builds as an "Available Software Site". I ran the check for updates and applied what was available. This fixed the issue.

My current environment is not stable against future updates. That is, on an earlier attempt, after succeeding as described above, I checked for further updates, which were found. Applying those updates broke the Eclipse installation and it wouldn't start. I don't have any idea how conflicting updates between the 4.37 (2025-09) and 4.38 (2025-12) releases are handled. But, my plan is not to look for further updates until 2025-12 is released and I install that. I chose this route rather than making the effort to downgrade to Sequoia.

I would recommend that Eclipse developers wait to update to Tahoe until the dust settles on this. Perhaps, wait for the 2025-12 official release which will have this fix.

 

[SDAVE]

Never upgrade a production machine to anything below .3 at least.

In real production environments, companies don't even upgrade for a year.

 

[svenmany]

Never upgrade a production machine to anything below .3 at least.

In real production environments, companies don't even upgrade for a year.

I agree, it's always easiest to let others find the problems for you and benefit from their work. The other approach is to participate, debug, and share the information.

Luckily, others do step in and get the work done. If no one had tried upgrading till .3, then the Eclipse problem would have reared its head at that point. Actual developers, working in real production environments, reported the problem.