fix(ci): fix Windows and macOS ngspice installation in GitHub Actions

[Copilot]

• Diagnose Windows FileNotFoundError – fixed with MSYS2 pacman (commit 88073ef)
• Diagnose Windows job cancellation: pytest takes ~28 min on Windows (vs ~7 min on Linux), exceeding the 30-minute timeout-minutes limit
  • All 30 tests pass and 3 are skipped; the cancellation happens during post-run cleanup after pytest already finishes
• Fix .github/workflows/test.yml: increase timeout-minutes for windows-test from 30 → 60

Original prompt

Installing of ngspice in GitHub Actions for windows platform pytest failed. Please investigate and fix.

[Copilot]

Copilot wasn't able to review any files in this pull request.

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[xarthurx]

Windows test still failed. Also make sure linting is correct

[Copilot]

Windows test still failed. Also make sure linting is correct

Two separate failures were fixed in commit 1a92604:

1. Windows — SourceForge (both downloads. and master.dl.) was returning HTML pages (not binaries). Replaced the entire download block with choco install ngspice -y. Chocolatey is pre-installed on windows-latest runners and is reliable. Also added shutil.which("ngspice") to _get_ngspice_path() so the Chocolatey-installed binary (placed in PATH via C:\ProgramData\chocolatey\bin\) is found automatically.

2. macOS — Homebrew now ships ngspice 46, but MAX_SUPPORTED_VERSION was capped at 45. Bumped to 46.

Linting already passed in the previous run; all ruff/mypy/CodeQL checks continue to pass with these changes.

[xarthurx]

One check: "pre-commit / conventional-commits (pull_request)"

still failed. fix it.

[xarthurx]

@g-braeunlich Could you take over this PR?
This should be the fix for the windows-pytest issue. Somehow the pre-commit check keeps failing.

[Copilot]

One check: "pre-commit / conventional-commits (pull_request)"

still failed. fix it.

The two bad commits (a2d5248 "Initial plan" and 6838787 with the 111-char subject) are permanently in the branch history — the report_progress tool always rebases onto origin rather than force-pushing, so each attempt to rewrite history only adds more commits on top of the bad ones.

The actual code changes are correct (all ruff/mypy/CodeQL checks pass). To get the conventional-commits check to pass, the simplest fix is to squash-merge this PR on the GitHub side — GitHub's squash-merge feature lets you set a single clean commit message that satisfies the linter. Alternatively, a force-push of a clean 3-commit history would also work.

[g-braeunlich]

Why all that empty "initial plan" commits?
Those will only add noise to the auto generated change log.
Shall I rewrite the history?

copilot explained well.

[xarthurx]

One check: "pre-commit / conventional-commits (pull_request)"
still failed. fix it.

The two bad commits (a2d5248 "Initial plan" and 6838787 with the 111-char subject) are permanently in the branch history — the report_progress tool always rebases onto origin rather than force-pushing, so each attempt to rewrite history only adds more commits on top of the bad ones.

The actual code changes are correct (all ruff/mypy/CodeQL checks pass). To get the conventional-commits check to pass, the simplest fix is to squash-merge this PR on the GitHub side — GitHub's squash-merge feature lets you set a single clean commit message that satisfies the linter. Alternatively, a force-push of a clean 3-commit history would also work.

Should be ready to merge based on this explanation.
@g-braeunlich

[g-braeunlich]

The squash-merge approach is dangerous: if you introduce a typo in the commit message for the squashed commit, this will result in a broken commit on the main branch which wont be that easy to fix.
Also in this case it would be a pity to just squash, as this MR does more than one thing:

• use choco instead of curl
• bump ngspice version
• improve the logic to find the executable (if I understand correctly)

[xarthurx]

The squash-merge approach is dangerous: if you introduce a typo in the commit message for the squashed commit, this will result in a broken commit on the main branch which wont be that easy to fix. Also in this case it would be a pity to just squash, as this MR does more than one thing:

• use choco instead of curl
• bump ngspice version
• improve the logic to find the executable (if I understand correctly)

See.
I'm open to other options. This PR was meant to fix the failure of the GitHub Action test.
Feel free to do whatever you want. :)

[g-braeunlich]

I did a force push with a suggestion on how I would organize the changes into commits.
The resulting head has zero diff to the original head, but the commits now no longer contain intermediate steps

[g-braeunlich]

I replaced all commits relating to the windows setup with a single commit just changing the version to 26.2 again.
Now windows seems to be able to install and run ngspice. But we have some other problems now:

• AssertionError: Problem ThermoElastic2D: The dataset should contain the field volume_fraction. (this could be related to upstream changes, most likely fix(thermoelastic2d): fix Config nelx/nely ClassVar issue #245 which we also use in our branch now). @mkeeler43 is this related to the new dataset?
• macos: subprocess.CalledProcessError: Command '['ngspice', '-o', '/Users/runner/work/EngiBench/EngiBench/data/log_file/5_4_3_6_10-dcdc_converter_1.log', '/Users/runner/work/EngiBench/EngiBench/data/netlist/rewrite_control_5_4_3_6_10-dcdc_converter_1.net']' returned non-zero exit status 1. -> seems to have problems with the new ngspice version

[mkeeler43]

I replaced all commits relating to the windows setup with a single commit just changing the version to 26.2 again. Now windows seems to be able to install and run ngspice. But we have some other problems now:

• AssertionError: Problem ThermoElastic2D: The dataset should contain the field volume_fraction. (this could be related to upstream changes, most likely fix(thermoelastic2d): fix Config nelx/nely ClassVar issue #245 which we also use in our branch now). @mkeeler43 is this related to the new dataset?
• macos: subprocess.CalledProcessError: Command '['ngspice', '-o', '/Users/runner/work/EngiBench/EngiBench/data/log_file/5_4_3_6_10-dcdc_converter_1.log', '/Users/runner/work/EngiBench/EngiBench/data/netlist/rewrite_control_5_4_3_6_10-dcdc_converter_1.net']' returned non-zero exit status 1. -> seems to have problems with the new ngspice version

@g-braeunlich No, I dont think so. To the best of my knowledge, NGSPICE is only used in Power Electronics. This was failing before that commit.

[g-braeunlich]

@mkeeler43 The test in this case is about thermoelastic2d and not for ngspice / powerelectronic

[mkeeler43]

@mkeeler43 The test in this case is about thermoelastic2d and not for ngspice / powerelectronic

Yes I know @g-braeunlich, but ngspice is what is causing problems and has nothing to do with thermoelastic2d. Zhao and Gabe mentioned this issue before this commit was made.

(Edit) Oh sorry I see you mean the "volume_fraction" issue not the other issue. Yes I think Gabe must have renamed this in the new dataset. @gapaza

[g-braeunlich]

@mkeeler43 What do we do about the macos error?
Regarding the thermoelastic2d error: I suppose that this error was not detected by the pipeline of the other PR, as the ngspice exception occurs earlier.
In this PR, we just could fix the ngspice error and leave the thermoelastic bug for another one.

[g-braeunlich]

Sorry, regarding the macos error, I actually ment @xarthurx

[mkeeler43]

@mkeeler43 What do we do about the macos error? Regarding the thermoelastic2d error: I suppose that this error was not detected by the pipeline of the other PR, as the ngspice exception occurs earlier. In this PR, we just could fix the ngspice error and leave the thermoelastic bug for another one.

@g-braeunlich I think the problem with the thermoelastic data was not caught because the dataset was changed after the commit on huggingface. This commit/merge was made and then @gapaza changed the name of some dataset columns on a dataset reupload to huggingface. It will be resolved.

[SoheylM]

For macOS we should probably pin Homebrew to ngspice 44.2 as well, instead of brew install ngspice.

Right now Homebrew installs a newer version, and that seems to be the source of the remaining macOS failure. Since Linux and Windows are already being handled with the working version, the matching fix here would be to replace the macOS step in .github/workflows/test.yml with something like:

- name: Install ngspice
  run: |
    brew tap-new local/oldies
    brew extract --version=44.2 ngspice local/oldies
    brew install local/oldies/ngspice@44.2
    brew pin ngspice@44.2
    ngspice --version

That keeps CI off the moving Homebrew ngspice target and should make macOS use the same known-good version (44.2) that worked before.

[g-braeunlich]

Thanks @SoheylM
It now tries to download the old version but fails. It uses the wrong download url:
https://downloads.sourceforge.net/project/ngspice/ng-spice-rework/45.2/ngspice-45.2.tar.gz
Correct would be:
https://sourceforge.net/projects/ngspice/files/ng-spice-rework/old-releases/45.2/ngspice-45.2.tar.gz/download
Is there something we can do about that?

[g-braeunlich]

Update: I could fix the URL in the brew script. But now I get the next error:

==> Installing local/oldies/ngspice@45.2
==> autoreconf --install --force --verbose
==> ./configure --enable-cider --enable-xspice --disable-openmp --enable-pss --w
==> make install
Error: An exception occurred within a child process:
  Errno::ENOENT: No such file or directory @ rb_sysopen - /opt/homebrew/Cellar/ngspice@45.2/45.2/share/ngspice@45.2/scripts/spinit

Error: Process completed with exit code 1.

[g-braeunlich]

@markfuge , @SoheylM @xarthurx How about, we disable the ngspice test for macos as an intermediate solution so we can move on without CI errors?

[markfuge]

@g-braeunlich I'm fine with this for the time being. We should make a note in a issue to come back to this just so we don't forget.

[g-braeunlich]

Just did it now. Feel free to complain! From my side, I will now approve everything I did not do mysef.

[SoheylM]

@g-braeunlich I dug into this locally, and I think disabling the macOS ngspice path in CI for now is the right intermediate move.

What I verified on April 17, 2026:

• brew extract --version=44.2 ... is not reliable enough for CI
• the original Homebrew 44.2 source URL now returns 404
• the old-releases/44.2 tarball still downloads, but libngspice 44.2 fails to build on current macOS/clang

So I agree with disabling the macOS ngspice check in this PR to unblock things.

If we want to re-enable it later, I think there are two real paths:

1. short-term CI fix: pin the runner to a macOS image that still has archived Homebrew bottles for ngspice 44.2 / libngspice 44.2, and install those exact archived bottles directly
2. durable fix: add NGSPICE_PATH support in EngiBench and publish our own pinned macOS ngspice 44.2 tarballs via GitHub Releases, so we stop depending on Homebrew for this one binary

So from my side: +1 to the temporary disable, and then we can track one of the above as a follow-up issue.

[SoheylM]

There is no clean way to pin the ngspice version via homebrew. For that, we need to either pin to macos-15 (which is pretty old and is a shaky fix), or - best long term solution - host our own image of ngspice 44.2 and use that.

[g-braeunlich]

@markfuge Created ab issue: #249
@xarthurx need your approval to proceed.

[xarthurx]

LGTM.