Termux Can’t Access External Storage Properly – Git Clone Error

Cletip

Hello everyone.

I’m new to GrapheneOS, and I’m currently trying to do something very specific: clone a git repo located on an external storage device into Termux using the “git clone” command.

To do this, I tested with two devices:

one where it works, with a “regular” Android version (Realme GT Master Edition)
the other with GrapheneOS (Pixel 9 Pro XL)

Both have the same Termux version: 0.118.3
I’m using external storage formatted in exFAT, accessible from both file explorers.
I’m also using the same permissions for Termux.

Here’s the process I followed to make it work on the Android phone (based on the Termux wiki: https://wiki.termux.com/wiki/Internal_and_external_storage):

That is:

allow Termux in Settings > App > Special permissions > All files access
enable OTG on my phone
run “termux-setup-storage” in Termux

That gives me, in $HOME/storage, the folder “external-1”, which directly points to the external storage.

I can also access it with (note the path from the root):
cd /storage/XXXX-XXXX/Android/data/com.termux/files/
where XXXX-XXXX is the UUID of the external storage.

Then I just need to run:
git clone storage/external-1/path/to/the/gitrepo

I got the error:
fatal: detected dubious ownership in repository at '/storage/XXXX-XXXX/path/to/the/gitrepo'

I simply did what git suggested:

git config --global --add safe.directory /storage/XXXX-XXXX/path/to/the/gitrepo

And then the git clone command worked!

That’s the normal process to make it work.

Now, let’s see what doesn’t work on GrapheneOS. I am using Termux with the owner Profile.
I plug in my USB drive (no need to enable OTG), it’s detected in the file explorer.

I think there are two possible issues:

First issue: with termux-setup-storage, I never managed to get the folder
$HOME/storage/external-1
The other folders appear fine, but external-1 never shows up.

Second issue:
I can’t access anything with the path /storage/XXXX-XXXX/
But I can find it in /mnt/media_rw/XXXX-XXXX/
I can go inside, add files, modify them, do cp -r to $HOME... Perfect.
But, when I tried :
git clone /mnt/media_rw/XXXX-XXXX/path/to/the/gitrepo

Error:

fatal: detected dubious ownership in repository at '/storage/XXXX-XXXX/path/to/the/gitrepo'

I did what git suggested, like on the other device:

git config --global --add safe.directory /mnt/media_rw/XXXX-XXXX/path/to/the/gitrepo

Then I try git clone again...
And the error persists.
I even tried:
git config --global --add safe.directory '*'
Or other globs, nothing works: same error, same attempt, but not the same behavior.

Also, the command termux-usb -l gives me: “dev/bus/usb/XXX/XXX”. That’s the same result as on the other phone, which means the external storage is indeed “detected”.
Finally, when I’m in /mnt/media_rw/XXXX-XXXX/, I can’t run “git init” in a subfolder. I don’t really understand why, since I can create and delete files there, but that can maybe help to add some context to this error.

I’ve tried enabling on GrapheneOS:

USB debugging
USB exploit: ON
checking developer options for “compatibility changes” for Termux: found nothing.

So, that’s everything I’ve tried : maybe I’m missing something obvious, but right now I can’t figure it out.

What am I missing?

Thanks in advance for any help

void0

I tried something similar after moving back to termux from the android terminal. I symbolically linked a folder on my device in an attempt to replace the termux home dir. I received quite a number of dubious filesystem errors especially when using git or compiling code and I decided to scrap the idea, instead chosing to use a simple rsync script to mirror the local termux dir to an external on-device dir.

TLDR: You'll probably have to give up making /mnt your work dir and rather use the directories termux provides you.