Graceful unmount failed when sending SIGTERM signal (fusermount3 permission denied)

[Silverlan]

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Summary

When trying to unmount a mounted vault, a permission denied error is shown.

What software is involved?

• Operating System: Ubuntu 24.04.1 LTS
• Cryptomator CLI: 0.6.1

Volume Type

FUSE

Steps to Reproduce

1. Mount the cryptomator vault:

./cryptomator-cli unlock --password:stdin --mounter=org.cryptomator.frontend.fuse.mount.LinuxFuseMountProvider --mountPoint=/test/cryptomator /test/cryptmator/cryptomator_vault

2. Unmount the cryptomator vault by pressing ctrl +c

I'm connected via a SSH client, but I don't think that matters. I'm logged in as root. It doesn't matter if I run the command with sudo or not, the error appears regardless.

Expected Behavior

I expected the vault to be unmounted gracefully.

Actual Behavior

The error message appears.
The target location still appears to be unmounted properly, however. At the very least the target location no longer contains any files.

Reproducibility

Always

Relevant Log Output

root@******:/test/cryptomator-cli/bin# ./cryptomator-cli unlock --password:stdin --mounter=org.cryptomator.frontend.fuse.mount.LinuxFuseMountProvider --mountPoint=/test/cryptomator /test/cryptomator_vault
Enter value for --password:stdin (Passphrase, read from STDIN):


[main] INFO  o.c.cli.Unlock - Unlocked and mounted vault successfully to file:///test/cryptomator/
^C[Thread-2] ERROR o.c.cli.Unlock - GRACEFUL UNMOUNT FAILED. Please check if manual cleanups are necessary
org.cryptomator.integrations.mount.UnmountFailedException: java.io.IOException: Cannot run program "fusermount3" (in directory "/test"): error=13, Permission denied
        at org.cryptomator.frontend.fuse@5.0.2/org.cryptomator.frontend.fuse.mount.LinuxFuseMountProvider$LinuxFuseMountBuilder$LinuxFuseMountedVolume.unmount(LinuxFuseMountProvider.java:153)
        at org.cryptomator.frontend.fuse@5.0.2/org.cryptomator.frontend.fuse.mount.LinuxFuseMountProvider$LinuxFuseMountBuilder$LinuxFuseMountedVolume.close(LinuxFuseMountProvider.java:167)
        at org.cryptomator.cli@0.6.1/org.cryptomator.cli.Unlock.teardown(Unlock.java:97)
        at org.cryptomator.cli@0.6.1/org.cryptomator.cli.Unlock.lambda$call$0(Unlock.java:88)
        at java.base/java.lang.Thread.run(Unknown Source)
Caused by: java.io.IOException: Cannot run program "fusermount3" (in directory "/test"): error=13, Permission denied
        at java.base/java.lang.ProcessBuilder.start(Unknown Source)
        at java.base/java.lang.ProcessBuilder.start(Unknown Source)
        at org.cryptomator.frontend.fuse@5.0.2/org.cryptomator.frontend.fuse.mount.LinuxFuseMountProvider$LinuxFuseMountBuilder$LinuxFuseMountedVolume.unmount(LinuxFuseMountProvider.java:145)
        ... 4 common frames omitted
Caused by: java.io.IOException: error=13, Permission denied
        at java.base/java.lang.ProcessImpl.forkAndExec(Native Method)
        at java.base/java.lang.ProcessImpl.<init>(Unknown Source)
        at java.base/java.lang.ProcessImpl.start(Unknown Source)
        ... 7 common frames omitted

Anything else?

I tried to do manual cleanup as described in https://github.com/cryptomator/cli?tab=readme-ov-file#manual-cleanup :
fusermount -u /test/cryptomator

But this just says:

fusermount: failed to unmount /test/cryptomator: Invalid argument