gpg "failed to write commit object"

Question

I'm trying to enable commit signing on OS X Mojave.

git commit -S -am "Test"

The error is:

error: gpg failed to sign the data
fatal: failed to write commit object

What I tried:

gpg works fine (see below), did not install gpg1 or gpg2
Installed GPG KeyChain and added a new key (even added a separate sign-only subkey whithin)
Installed pinentry
gpg2 --clearsign works fine (generates a new .asc file for files, outputs text for plain text)

Questions I looked into and tried every option:

What am I doing wrong?

if you are looking to get added to a repo instead of init git-crypt in your repo, youll need to let someone who already has access to the encrypted files to add your public key to the `/.git-crypt/...` part of the repo — mewc, May 06 '20 at 03:22
Thanks @mewc, but that was not the case, see my own answer below — Alex Buznik, May 06 '20 at 10:20
Cool, more of an fyi for the next person. Didnt feel it deserved its own answer. — mewc, May 07 '20 at 00:59

score 46 · Answer 1 · edited Aug 10 '19 at 19:25

46

I also had this problem. I found a good solution. Just try to sign a file before you commit.

$ touch a.txt
$ gpg --sign a.txt

Then, the OS will let you input the password. If this step is OK, now you can commit by signing correctly.

edited Aug 10 '19 at 19:25

Wasi

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answered Aug 10 '19 at 14:21

mkckr0

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Thanks, it saved me a lot of time! – dgebert Feb 19 '21 at 10:49
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But why is this needed? – Koray Tugay Jul 07 '21 at 03:06
This worked, but why this has to be done? Is this a bug? – pradpi Oct 04 '21 at 11:00
Thanks! This helped me figure out the true issue: my terminal window was too small to render the password prompt. It seems like `git` sometimes hides the error information from surfacing. – TheLandolorien Jan 24 '22 at 21:58
Brilliant, saved me the trouble of doing all of this: https://stackoverflow.com/questions/39494631/gpg-failed-to-sign-the-data-fatal-failed-to-write-commit-object-git-2-10-0 – PaulIsLoud May 05 '22 at 07:24

score 18 · Answer 2 · edited Aug 19 '19 at 02:59

18

I just added the key ID to the global config

list all keys:

gpg --list-keys

Select the one you added to github and set it.

git config --global user.signingkey [public key ID]

edited Aug 19 '19 at 02:59

MewX

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answered Jul 08 '19 at 15:39

Zacbe Gonzalez

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score 4 · Accepted Answer · answered Mar 07 '19 at 07:08

4

Heh, of course, right after I posted this question, I found the solution.

So my problem was that I followed this doc: https://help.github.com/en/articles/telling-git-about-your-signing-key

And set up both GPG and smimesign, when I have Git < 2.19 and no proper X.509 keys.

So I just removed the part with smimesign from global ~/.gitconfig

answered Mar 07 '19 at 07:08

Alex Buznik

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Exact solution for could not find the user id in specified key while commiting – Sasi Dhivya Aug 16 '21 at 16:36

score 2 · Answer 4 · answered Feb 26 '22 at 16:43

Try with echo "foobar" | gpg --clearsign. It should ask for your key's passphrase and return the signature. If instead you see the following error message:

error: gpg failed to sign the data
fatal: failed to write commit object

You might want to try running export GPG_TTY=$(tty). If after testing again you're prompted for the password and it works, run this everytime on startup, adding it to ~/.bashrc, which is actually required according to gpg-agent's documentation, as mentioned in this dev.gnupg thread and which you can verify with man gpg-agent.

I also found this gitHub gist very useful.

gpg "failed to write commit object"

4 Answers4

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