fdroid build --all failed: env['SOURCE_DATE_EPOCH'] = get_source_date_epoch(get_build_dir(app)) str expected, not NoneType

yesseruser
2026-03-14T21:05:16Z

Running `fdroid build -v --all` in [this repo](https://github.com/yesser-studios/f-droid-repo) (after `cd fdroid`) the following is output:
```
2026-03-12 21:43:56,188 DEBUG: Reading 'config.yml'
2026-03-12 21:43:56,191 INFO: Using /usr/local/lib/android/sdk/build-tools/36.1.0/apksigner
2026-03-12 21:43:56,297 WARNING: unsafe permissions on 'config.yml' (should be 0600)!
2026-03-12 21:43:56,297 INFO: Creating log directory
2026-03-12 21:43:56,297 INFO: Creating temporary directory
2026-03-12 21:43:56,297 INFO: Creating output directory
2026-03-12 21:43:56,298 DEBUG: skip deploying full build logs: not enabled in config
2026-03-12 21:43:56,298 INFO: Creating build directory
2026-03-12 21:43:56,308 DEBUG: skip deploying full build logs: not enabled in config
2026-03-12 21:43:56,308 DEBUG: Getting git vcs interface for https://github.com/yesseruser/death-switch-android
2026-03-12 21:43:56,308 DEBUG: Checking com.yesser_studios.death_switch:1
2026-03-12 21:43:56,308 INFO: Building version 1.3.0 (1) of com.yesser_studios.death_switch
2026-03-12 21:43:56,308 DEBUG: sys.platform='linux', git_executable='git'
2026-03-12 21:43:56,308 WARNING: NoSuchPathError: build/com.yesser_studios.death_switch
2026-03-12 21:43:56,310 ERROR: Could not build app com.yesser_studios.death_switch due to unknown error: Traceback (most recent call last):
File "/home/runner/.local/lib/python3.12/site-packages/fdroidserver/build.py", line 1198, in main
if trybuild(app, build, build_dir, output_dir, log_dir,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/runner/.local/lib/python3.12/site-packages/fdroidserver/build.py", line 941, in trybuild
build_local(app, build, vcs, build_dir, output_dir, log_dir, srclib_dir, extlib_dir, tmp_dir, force, onserver, refresh)
File "/home/runner/.local/lib/python3.12/site-packages/fdroidserver/build.py", line 482, in build_local
common.set_FDroidPopen_env(app, build)
File "/home/runner/.local/lib/python3.12/site-packages/fdroidserver/common.py", line 3288, in set_FDroidPopen_env
env['SOURCE_DATE_EPOCH'] = get_source_date_epoch(get_build_dir(app))
~~~^^^^^^^^^^^^^^^^^^^^^
File "", line 690, in __setitem__
File "", line 764, in encode
TypeError: str expected, not NoneType

2026-03-12 21:43:56,311 DEBUG: skip deploying full build logs: not enabled in config
2026-03-12 21:43:56,311 DEBUG: skip deploying full build logs: not enabled in config
2026-03-12 21:43:56,311 INFO: Finished
2026-03-12 21:43:56,311 INFO: 1 build failed
2026-03-12 21:43:56,312 DEBUG: skip deploying full build logs: not enabled in config
2026-03-12 21:43:56,312 DEBUG: skip deploying full build logs: not enabled in config

```
[Here](https://github.com/yesser-studios/f-droid-repo/actions/runs/23025315697/job/66871651366)'s the full log of the GitHub workflow I used to build this.

When trying locally and setting SOURCE_DATE_EPOCH manually, nothing changed. I am not sure what to do, but building the same manifest from the fdroiddata repo (after I copy it) doesn't throw this issue.