Fix Simple Auth Manager UI dev server not starting in breeze

[choo121600]

Problem

Second Vite dev server (Simple Auth Manager UI) never starts in breeze dev mode

Change

• Change subprocess.run --> subprocess.Popen for the first pnpm dev
• Add signal.pause() to keep the script alive so child processes stay in the same process group

Screen.Recording.2026-01-22.at.6.13.08.PM.mov

closes: #60930

---

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

Generated-by: [claude] following the guidelines

---

• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst or {issue_number}.significant.rst, in airflow-core/newsfragments.

[ephraimbuddy]

@pierrejeambrun, it seems I'm not alone in this issue. Similar to the reverted fix: #60786

[potiuk]

Nice. TIl about pause()

[choo121600]

Redirected prek output to file in dev mode.
Redirecting to file makes prek skip the indicator and keeps logs available for debugging.

[pierrejeambrun]

I think this problem is specific to --use-mprocs.

I tried both on main and can't reproduce, but if this fixes it for your setup go for it.

I tried this PR locally and both are working for me.

[choo121600]

@pierrejeambrun Thanks for checking!
From my investigation, this issue does not seem to be specific to the --use-mprocs option. I can reproduce the same behavior even when running inside a tmux session.

Screen.Recording.2026-01-24.at.2.29.32.PM.mov

Regarding the point @potiuk mentioned about “Compile UI assets in dev mode” being overridden in the terminal, this appears to be related to a prek version upgrade.
I did not see this behavior with prek==0.2.22, but started experiencing it after upgrading to 0.3.0.

Screen.Recording.2026-01-24.at.2.48.39.PM.mov

[choo121600]

@ephraimbuddy would you mind checking this as well when you have time?

[github-actions]

Backport successfully created: v3-1-test

Status	Branch	Result
✅	v3-1-test

[choo121600]

Problem

Second Vite dev server (Simple Auth Manager UI) never starts in breeze dev mode

Change

• Change subprocess.run --> subprocess.Popen for the first pnpm dev
• Add signal.pause() to keep the script alive so child processes stay in the same process group

Screen.Recording.2026-01-22.at.6.13.08.PM.mov

closes: #60930

---

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

Generated-by: [claude] following the guidelines

---

• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst or {issue_number}.significant.rst, in airflow-core/newsfragments.

[ephraimbuddy]

@pierrejeambrun, it seems I'm not alone in this issue. Similar to the reverted fix: #60786

[potiuk]

Nice. TIl about pause()

[choo121600]

Redirected prek output to file in dev mode.
Redirecting to file makes prek skip the indicator and keeps logs available for debugging.

[pierrejeambrun]

I think this problem is specific to --use-mprocs.

I tried both on main and can't reproduce, but if this fixes it for your setup go for it.

I tried this PR locally and both are working for me.

[choo121600]

@pierrejeambrun Thanks for checking!
From my investigation, this issue does not seem to be specific to the --use-mprocs option. I can reproduce the same behavior even when running inside a tmux session.

Screen.Recording.2026-01-24.at.2.29.32.PM.mov

Regarding the point @potiuk mentioned about “Compile UI assets in dev mode” being overridden in the terminal, this appears to be related to a prek version upgrade.
I did not see this behavior with prek==0.2.22, but started experiencing it after upgrading to 0.3.0.

Screen.Recording.2026-01-24.at.2.48.39.PM.mov

[choo121600]

@ephraimbuddy would you mind checking this as well when you have time?

[github-actions]

Backport successfully created: v3-1-test

Status	Branch	Result
✅	v3-1-test

[choo121600]

Problem

Second Vite dev server (Simple Auth Manager UI) never starts in breeze dev mode

Change

• Change subprocess.run --> subprocess.Popen for the first pnpm dev
• Add signal.pause() to keep the script alive so child processes stay in the same process group

Screen.Recording.2026-01-22.at.6.13.08.PM.mov

closes: #60930

---

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

Generated-by: [claude] following the guidelines

---

• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst or {issue_number}.significant.rst, in airflow-core/newsfragments.

[ephraimbuddy]

@pierrejeambrun, it seems I'm not alone in this issue. Similar to the reverted fix: #60786

[potiuk]

Nice. TIl about pause()

[choo121600]

Redirected prek output to file in dev mode.
Redirecting to file makes prek skip the indicator and keeps logs available for debugging.

[pierrejeambrun]

I think this problem is specific to --use-mprocs.

I tried both on main and can't reproduce, but if this fixes it for your setup go for it.

I tried this PR locally and both are working for me.

[choo121600]

@pierrejeambrun Thanks for checking!
From my investigation, this issue does not seem to be specific to the --use-mprocs option. I can reproduce the same behavior even when running inside a tmux session.

Screen.Recording.2026-01-24.at.2.29.32.PM.mov

Regarding the point @potiuk mentioned about “Compile UI assets in dev mode” being overridden in the terminal, this appears to be related to a prek version upgrade.
I did not see this behavior with prek==0.2.22, but started experiencing it after upgrading to 0.3.0.

Screen.Recording.2026-01-24.at.2.48.39.PM.mov

[choo121600]

@ephraimbuddy would you mind checking this as well when you have time?

[github-actions]

Backport successfully created: v3-1-test

Status	Branch	Result
✅	v3-1-test

[choo121600]

Problem

Second Vite dev server (Simple Auth Manager UI) never starts in breeze dev mode

Change

• Change subprocess.run --> subprocess.Popen for the first pnpm dev
• Add signal.pause() to keep the script alive so child processes stay in the same process group

Screen.Recording.2026-01-22.at.6.13.08.PM.mov

closes: #60930

---

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

Generated-by: [claude] following the guidelines

---

• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst or {issue_number}.significant.rst, in airflow-core/newsfragments.

[ephraimbuddy]

@pierrejeambrun, it seems I'm not alone in this issue. Similar to the reverted fix: #60786

[potiuk]

Nice. TIl about pause()

[choo121600]

Redirected prek output to file in dev mode.
Redirecting to file makes prek skip the indicator and keeps logs available for debugging.

[pierrejeambrun]

I think this problem is specific to --use-mprocs.

I tried both on main and can't reproduce, but if this fixes it for your setup go for it.

I tried this PR locally and both are working for me.

[choo121600]

@pierrejeambrun Thanks for checking!
From my investigation, this issue does not seem to be specific to the --use-mprocs option. I can reproduce the same behavior even when running inside a tmux session.

Screen.Recording.2026-01-24.at.2.29.32.PM.mov

Regarding the point @potiuk mentioned about “Compile UI assets in dev mode” being overridden in the terminal, this appears to be related to a prek version upgrade.
I did not see this behavior with prek==0.2.22, but started experiencing it after upgrading to 0.3.0.

Screen.Recording.2026-01-24.at.2.48.39.PM.mov

[choo121600]

@ephraimbuddy would you mind checking this as well when you have time?

[github-actions]

Backport successfully created: v3-1-test

Status	Branch	Result
✅	v3-1-test

[choo121600]

Problem

Second Vite dev server (Simple Auth Manager UI) never starts in breeze dev mode

Change

• Change subprocess.run --> subprocess.Popen for the first pnpm dev
• Add signal.pause() to keep the script alive so child processes stay in the same process group

Screen.Recording.2026-01-22.at.6.13.08.PM.mov

closes: #60930

---

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

Generated-by: [claude] following the guidelines

---

• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst or {issue_number}.significant.rst, in airflow-core/newsfragments.

[ephraimbuddy]

@pierrejeambrun, it seems I'm not alone in this issue. Similar to the reverted fix: #60786

[potiuk]

Nice. TIl about pause()

[choo121600]

Redirected prek output to file in dev mode.
Redirecting to file makes prek skip the indicator and keeps logs available for debugging.

[pierrejeambrun]

I think this problem is specific to --use-mprocs.

I tried both on main and can't reproduce, but if this fixes it for your setup go for it.

I tried this PR locally and both are working for me.

[choo121600]

@pierrejeambrun Thanks for checking!
From my investigation, this issue does not seem to be specific to the --use-mprocs option. I can reproduce the same behavior even when running inside a tmux session.

Screen.Recording.2026-01-24.at.2.29.32.PM.mov

Regarding the point @potiuk mentioned about “Compile UI assets in dev mode” being overridden in the terminal, this appears to be related to a prek version upgrade.
I did not see this behavior with prek==0.2.22, but started experiencing it after upgrading to 0.3.0.

Screen.Recording.2026-01-24.at.2.48.39.PM.mov

[choo121600]

@ephraimbuddy would you mind checking this as well when you have time?

[github-actions]

Backport successfully created: v3-1-test

Status	Branch	Result
✅	v3-1-test

[choo121600]

Problem

Second Vite dev server (Simple Auth Manager UI) never starts in breeze dev mode

Change

• Change subprocess.run --> subprocess.Popen for the first pnpm dev
• Add signal.pause() to keep the script alive so child processes stay in the same process group

Screen.Recording.2026-01-22.at.6.13.08.PM.mov

closes: #60930

---

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

Generated-by: [claude] following the guidelines

---

• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst or {issue_number}.significant.rst, in airflow-core/newsfragments.

[ephraimbuddy]

@pierrejeambrun, it seems I'm not alone in this issue. Similar to the reverted fix: #60786

[potiuk]

Nice. TIl about pause()

[choo121600]

Redirected prek output to file in dev mode.
Redirecting to file makes prek skip the indicator and keeps logs available for debugging.

[pierrejeambrun]

I think this problem is specific to --use-mprocs.

I tried both on main and can't reproduce, but if this fixes it for your setup go for it.

I tried this PR locally and both are working for me.

[choo121600]

@pierrejeambrun Thanks for checking!
From my investigation, this issue does not seem to be specific to the --use-mprocs option. I can reproduce the same behavior even when running inside a tmux session.

Screen.Recording.2026-01-24.at.2.29.32.PM.mov

Regarding the point @potiuk mentioned about “Compile UI assets in dev mode” being overridden in the terminal, this appears to be related to a prek version upgrade.
I did not see this behavior with prek==0.2.22, but started experiencing it after upgrading to 0.3.0.

Screen.Recording.2026-01-24.at.2.48.39.PM.mov

[choo121600]

@ephraimbuddy would you mind checking this as well when you have time?

[github-actions]

Backport successfully created: v3-1-test

Status	Branch	Result
✅	v3-1-test

[choo121600]

Problem

Second Vite dev server (Simple Auth Manager UI) never starts in breeze dev mode

Change

• Change subprocess.run --> subprocess.Popen for the first pnpm dev
• Add signal.pause() to keep the script alive so child processes stay in the same process group

Screen.Recording.2026-01-22.at.6.13.08.PM.mov

closes: #60930

---

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

Generated-by: [claude] following the guidelines

---

• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst or {issue_number}.significant.rst, in airflow-core/newsfragments.

[ephraimbuddy]

@pierrejeambrun, it seems I'm not alone in this issue. Similar to the reverted fix: #60786

[potiuk]

Nice. TIl about pause()

[choo121600]

Redirected prek output to file in dev mode.
Redirecting to file makes prek skip the indicator and keeps logs available for debugging.

[pierrejeambrun]

I think this problem is specific to --use-mprocs.

I tried both on main and can't reproduce, but if this fixes it for your setup go for it.

I tried this PR locally and both are working for me.

[choo121600]

@pierrejeambrun Thanks for checking!
From my investigation, this issue does not seem to be specific to the --use-mprocs option. I can reproduce the same behavior even when running inside a tmux session.

Screen.Recording.2026-01-24.at.2.29.32.PM.mov

Regarding the point @potiuk mentioned about “Compile UI assets in dev mode” being overridden in the terminal, this appears to be related to a prek version upgrade.
I did not see this behavior with prek==0.2.22, but started experiencing it after upgrading to 0.3.0.

Screen.Recording.2026-01-24.at.2.48.39.PM.mov

[choo121600]

@ephraimbuddy would you mind checking this as well when you have time?

[github-actions]

Backport successfully created: v3-1-test

Status	Branch	Result
✅	v3-1-test

[choo121600]

Problem

Second Vite dev server (Simple Auth Manager UI) never starts in breeze dev mode

Change

• Change subprocess.run --> subprocess.Popen for the first pnpm dev
• Add signal.pause() to keep the script alive so child processes stay in the same process group

Screen.Recording.2026-01-22.at.6.13.08.PM.mov

closes: #60930

---

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

Generated-by: [claude] following the guidelines

---

• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst or {issue_number}.significant.rst, in airflow-core/newsfragments.

[ephraimbuddy]

@pierrejeambrun, it seems I'm not alone in this issue. Similar to the reverted fix: #60786

[potiuk]

Nice. TIl about pause()

[choo121600]

Redirected prek output to file in dev mode.
Redirecting to file makes prek skip the indicator and keeps logs available for debugging.

[pierrejeambrun]

I think this problem is specific to --use-mprocs.

I tried both on main and can't reproduce, but if this fixes it for your setup go for it.

I tried this PR locally and both are working for me.

[choo121600]

@pierrejeambrun Thanks for checking!
From my investigation, this issue does not seem to be specific to the --use-mprocs option. I can reproduce the same behavior even when running inside a tmux session.

Screen.Recording.2026-01-24.at.2.29.32.PM.mov

Regarding the point @potiuk mentioned about “Compile UI assets in dev mode” being overridden in the terminal, this appears to be related to a prek version upgrade.
I did not see this behavior with prek==0.2.22, but started experiencing it after upgrading to 0.3.0.

Screen.Recording.2026-01-24.at.2.48.39.PM.mov

[choo121600]

@ephraimbuddy would you mind checking this as well when you have time?

[github-actions]

Backport successfully created: v3-1-test

Status	Branch	Result
✅	v3-1-test