macOS Tahoe 26.4 Server failed to start

[maxsommer]

Description

I'm running:

• macOS Tahoe 26.4
• Macbook Pro M1
• Downloaded latest release [v1.30.12](https://github.com/rustledger/rustfava/releases/tag/v1.30.12)

Program errors when opening .beancount file with:

Failed to open file: Error: Server failed to start

Steps to Reproduce

1. Download latest release
2. Open .beancount file that works fine in fava
3. Error appears

Rustfava Version

1.30.12

Python Version

3.14.4

Operating System

macOS

Additional Context

No response

[robcohen]

Thanks for the report @maxsommer.

The "Server failed to start" error means the bundled rustfava-server sidecar process failed to launch. To help us diagnose, could you provide a few things?

1. Check if macOS is blocking the binary:

Open Terminal and run:

xattr -l /Applications/Rustfava.app/Contents/MacOS/rustfava-server*

If you see com.apple.quarantine, try removing it:

xattr -cr /Applications/Rustfava.app

Then relaunch and see if the error persists.

2. Try launching the sidecar manually:

/Applications/Rustfava.app/Contents/MacOS/rustfava-server-aarch64-apple-darwin --help

Does it print anything, or do you get a permission/crash error?

3. Console logs:

Open Console.app, filter for "rustfava", then reproduce the error. Paste any relevant log lines here.

4. Did you install via the .dmg or by extracting the .app manually?

macOS Tahoe 26.4 may have tightened Gatekeeper restrictions. Knowing the install method helps narrow this down.

[maxsommer]

@robcohen thanks first of all.

1. Indeed macOS was blocking the binary, I executed the command to remove it from quarantine. Unfortunately this changed nothing – the server still fails to start.
2. While I was not able to execute the command you posted because the binary path you specified is not present with my .app container - I was able to run this one instead /Applications/Rustfava.app/Contents/MacOS/rustfava-server --help - it does print out the help menu properly:

Usage: rustfava-server [OPTIONS] [FILENAMES]...

  Start Rustfava for FILENAMES on http://<host>:<port>.

  If the `BEANCOUNT_FILE` environment variable is set, Rustfava will use the
  files (delimited by ';' on Windows and ':' on POSIX) given there in addition
  to FILENAMES.

  Note you can also specify command-line options via environment variables
  with the `RUSTFAVA_` prefix. For example, `--host=0.0.0.0` is equivalent to
  setting the environment variable `RUSTFAVA_HOST=0.0.0.0`.

Options:
  -p, --port <port>   The port to listen on.  [default: 5000]
  -H, --host <host>   The host to listen on.  [default: localhost]
  --prefix TEXT       Set an URL prefix.
  --incognito         Run in incognito mode and obscure all numbers.
  --read-only         Run in read-only mode, disable any change through
                      rustfava.
  -d, --debug         Turn on debugging.
  --profile           Turn on profiling. Implies --debug.
  --profile-dir PATH  Output directory for profiling data.
  --poll-watcher      Use old polling-based watcher.
  --version           Show the version and exit.
  --help              Show this message

3. I reproduced the scenario - and it yielded the following which I think is noteworthy but not surprising given the error surfaced to me anyway:

standard	21:29:51.235239+0200	rustfava-desktop	WebContent[16413]: [pageID=8, frameID=4294967297, resourceID=703] ResourceLoader::willSendRequestInternal: calling completion handler
standard	21:29:51.235272+0200	rustfava-desktop	WebContent[16413]: [pageID=8, frameID=4294967297, resourceID=703 SubResourceLoader::willSendRequestInternal: resource load finished; calling completion handler
standard	21:29:51.235277+0200	rustfava-desktop	WebContent[16413]: [webPageID=8, frameID=4294967297, resourceID=703] WebLoaderStrategy::scheduleLoad: URL will be scheduled with the NetworkProcess
standard	21:29:51.235281+0200	rustfava-desktop	WebContent[16413]: [webPageID=8, frameID=4294967297, resourceID=703] WebLoaderStrategy::scheduleLoad: Resource is being scheduled with the NetworkProcess (priority=2, existingNetworkResourceLoadIdentifierToResume=0)
standard	21:29:51.235285+0200	rustfava-desktop	WebContent[16413]: [webPageID=8, frameID=4294967297, resourceID=703] WebResourceLoader::WebResourceLoader
standard	21:29:51.241131+0200	rustfava-desktop	WebContent[16413]: [webPageID=8, frameID=4294967297, resourceID=703] WebResourceLoader::didFailResourceLoad
standard	21:29:51.241147+0200	rustfava-desktop	WebContent[16413]: [pageID=8, frameID=4294967297, resourceID=703 SubResourceLoader::didFail: (type=1, code=-1004)
standard	21:29:51.442608+0200	rustfava-desktop	WebContent[16413]: [pageID=8, frameID=4294967297, resourceID=704] ResourceLoader::willSendRequestInternal: calling completion handler
standard	21:29:51.442660+0200	rustfava-desktop	WebContent[16413]: [pageID=8, frameID=4294967297, resourceID=704 SubResourceLoader::willSendRequestInternal: resource load finished; calling completion handler
standard	21:29:51.442672+0200	rustfava-desktop	WebContent[16413]: [webPageID=8, frameID=4294967297, resourceID=704] WebLoaderStrategy::scheduleLoad: URL will be scheduled with the NetworkProcess
standard	21:29:51.442683+0200	rustfava-desktop	WebContent[16413]: [webPageID=8, frameID=4294967297, resourceID=704] WebLoaderStrategy::scheduleLoad: Resource is being scheduled with the NetworkProcess (priority=2, existingNetworkResourceLoadIdentifierToResume=0)
standard	21:29:51.442694+0200	rustfava-desktop	WebContent[16413]: [webPageID=8, frameID=4294967297, resourceID=704] WebResourceLoader::WebResourceLoader
standard	21:29:51.449968+0200	rustfava-desktop	WebContent[16413]: [webPageID=8, frameID=4294967297, resourceID=704] WebResourceLoader::didFailResourceLoad
standard	21:29:51.449989+0200	rustfava-desktop	WebContent[16413]: [pageID=8, frameID=4294967297, resourceID=704 SubResourceLoader::didFail: (type=1, code=-1004)

Note that this is just an excerpt, this repeats many times. Looks like it simply cannot load a resource from the server that needs to be started.
4. I did install via the .dmg file

One thing I just noticed as well - trying to load the sample beancount file fails with error Failed to open example file: Example file not found.