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@paolocarrasco
Last active November 5, 2024 20:08
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How to understand the `gpg failed to sign the data` problem in git

Problem

You have installed GPG, then tried to commit and suddenly you see this error message after it:

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

Debug

For understanding what's going on, first check what git is doing, so add GIT_TRACE=1 at the beginning of the command you used before (git commit or git rebase):

GIT_TRACE=1 git commit

With that you can see what GPG is doing: Probably you will see something like this

10:37:22.346480 run-command.c:637       trace: run_command: gpg --status-fd=2 -bsau <your GPG key>

(Check if your GPG key is correct)

Execute that gpg command again in the command line:

gpg --status-fd=2 -bsau <your GPG key>

👆🏻 With this now you could see what happened in detail!

Solutions

We can have many problems, but I list what I found:

  1. It could be that the GPG key was expired: https://stackoverflow.com/a/47561300/532912

  2. Another thing could be that the secret key was not set properly (In my case the message said gpg: signing failed: No secret key as it can be see in the image below). image It means that is not finding the key that was set. You would need to set up the GPG key in Git (again):

    • List the secret keys available in GPG.
    gpg --list-secret-keys --keyid-format=long
    • Copy your key
    • Set your key for your user in git
    git config --global user.signingkey <your key>
  3. Another popular solution that could help was shared here by @NirajanMahara: https://gist.github.com/paolocarrasco/18ca8fe6e63490ae1be23e84a7039374?permalink_comment_id=3767413#gistcomment-3767413

  4. You can see in the thread of this gist other ways to find the solution to other problems. I recommend to read the Github guide for signing commits with GPG.

Hope it helps!

@victorjatoba
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Follow the below url to setup signed commit https://help.github.com/en/articles/telling-git-about-your-signing-key

if still getting gpg failed to sign the data fatal: failed to write commit object

this is not issue with git ,this is with GPG follow below steps

  1. gpg --version
  2. echo "test" | gpg --clearsign

if it is showing:

gpg: signing failed: Inappropriate ioctl for device
gpg: [stdin]: clear-sign failed: Inappropriate ioctl for device
  1. then use export GPG_TTY=$(tty)
  2. then try again echo "test" | gpg --clearsign in which PGP signature is.

Output:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

test
-----BEGIN PGP SIGNATURE-----

iLMEAQEKAB0WIQS2V0SFHi18psvDbo7uFF+LP7qc1gUCYLjB2QAKCRDuFF+LP7qc
1r5LBACB1m3Lpl21379qAvVamWcn9isdgdg34t34t43t34t34t434yGQHqikxWL7A5
Ls7giKZYscb30o0rkY6I1W9MjBBW96R2pnaYsioFpsf434dfg54rfdgfdgdfgdfpaIoU3k
JKrYxR7yMjqUv0a2jE+97kh+bSuzqwIkMHyikbABI90lY+4OLw==
=UHKx
-----END PGP SIGNATURE-----
  1. git config -l | grep gpg

Output:

commit.gpgsign=true
gpg.program=gpg
tag.gpgsign=true
  1. apply git commit -S -m "initial commit rocketrocketrocketrocket"
  2. or git config --global commit.gpgsign true

https://stackoverflow.com/questions/39494631/gpg-failed-to-sign-the-data-fatal-failed-to-write-commit-object-git-2-10-0/55993078#55993078

It worked for me. Thanks!

@MaxFoton
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5. git config -l | grep gpg

it also worked for me! thank you!

@dan-developer
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It seems for every branch I have, I need to execute the export GPG_TTY=$(tty) command before committing.

Is there anyway around this?

It worked for me. Thank you!

@Phrozyn
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Phrozyn commented Oct 14, 2022

For me the issue is always simply the fact that my vscode terminal window is too small, git needs like half a screen's height and about the width of this comment section for it to surface the GPG prompt, otherwise it errors out and tells you that:

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

so I enlarge the window and voila all fixed when I run git commit again.

@Jeff-Tian
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There's another situation:

sec   dsa3072/AAAAAAAAAAAAA 2010-05-05 [SC] [expires: 2030-05-05]
      BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
uid                 [ultimate] Author Name <[email protected]>

While GitHub documentation operates with AAAAAAAAAAAAA in sections when you need to create and register the key in GPG, git requires BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB, i.e. git config --global user.signingkey BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB, instead of git config --global user.signingkey AAAAAAAAAAAAA

Hopefully, it helps someone.

It helped me, thanks!

@0xmovses
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worked for me thank you for this!

@pullsuzdesheloper
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Great! Thanks for your help!

@lucymonie
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lucymonie commented Oct 24, 2022

Thank you 🙏

@lnasc256
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thank you

@marionorthvolt
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I was trying to solve this for 2 days! thanks!

@Lippiece
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Lippiece commented Dec 2, 2022

  1. then use export GPG_TTY=$(tty)

It also helped to to set it permanently in ~/.profile on Ubuntu (to do so, append export GPG_TTY=$(tty) to the ~/.profile file).

@gcakir
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gcakir commented Dec 12, 2022

I had the same issue. The output of the command gpg --status-fd=2 -bsau was fine. It turns out my git config in the repo was the problematic. I deleted the [user] and [gpg] entries in .git/config, and then I reconfigured the pgp globally via git config --global gpg.program gpg and git config --global user.signingkey "<my signing key>" once again. Then it worked.

@truemiller
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4. echo "test" | gpg --clearsign

this worked for me +1

@sankita15
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I just killed the gpg-agent and started again and it worked for me

killall gpg-agent
gpg-agent daemon

@0x61nas
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0x61nas commented Jan 12, 2023

thanks, @paolocarrasco

@Honglin-Lu
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There's another situation:

sec   dsa3072/AAAAAAAAAAAAA 2010-05-05 [SC] [expires: 2030-05-05]
      BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
uid                 [ultimate] Author Name <[email protected]>

While GitHub documentation operates with AAAAAAAAAAAAA in sections when you need to create and register the key in GPG, git requires BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB, i.e. git config --global user.signingkey BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB, instead of git config --global user.signingkey AAAAAAAAAAAAA

Hopefully, it helps someone.

This solution also works for me. Thank you!

@lfbharat
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omg I just need to run export GPG_TTY=$(tty)

  1. then use export GPG_TTY=$(tty)

this one worked for me as well.

@LuciNyan
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LuciNyan commented Feb 1, 2023

3. then use export GPG_TTY=$(tty)

Thank you! it works for me!

@livaper
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livaper commented Feb 15, 2023

Thank You, @paolocarrasco

@rootsongjc
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It works. Thank you!

@rahulsaw2003
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gpg: skipped "D6F50106F5C8A98B": No secret key
gpg: signing failed: No secret key
error: gpg failed to sign the data
fatal: failed to write commit object

I am getting this error since few days, I have regenerated the gpg key many times. but still I am getting this error. What should I do to get rid of this error. Please help as soon as possible.

@rahulsaw2003
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@exostin
After struggling for hours, I finally get rid of this error.
Thanks man

@kennethsequeira
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@NirajanMahara lifesaver!
Your solution worked out for me.

@thyarles
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thyarles commented Mar 8, 2023

I you're on WSL2, maybe this can help:

  • Add those lines to ~/.gnupg/gpg.conf

    use-agent 
    pinentry-mode loopback
    
  • Add this line to ~/.gnupg/gpg-agent.conf

    allow-loopback-pinentry
    

@gauravk-io
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gauravk-io commented Apr 4, 2023

I was getting the error

gpg: skipped "29D277CEFE65F74E": No secret key
gpg: signing failed: No secret key
error: gpg failed to sign the data
fatal: failed to write commit object

I just need to set the

gpg.program="C:\Program Files (x86)\GnuPG\bin\gpg.exe"

to

gpg.program=gpg

THANKYOU @victorjatoba

@Riessarius
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This exactly solved my problem. Great thanks! @victorjatoba

@renjujv
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renjujv commented Apr 24, 2023

@pro-akim
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pro-akim commented May 2, 2023

Thanks @paolocarrasco, you are awesome

@igorsobot
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I just killed the gpg-agent and started again and it worked for me

killall gpg-agent
gpg-agent daemon

Yes, sometimes pinentry-mac update brakes gpg-agent

@T410
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T410 commented May 12, 2023

Additionally, if you are using a mac and you are experiencing an issue, try step number 8: https://docs.github.com/en/authentication/managing-commit-signature-verification/telling-git-about-your-signing-key?platform=mac

$ brew install pinentry-mac
$ echo "pinentry-program $(which pinentry-mac)" >> ~/.gnupg/gpg-agent.conf
$ killall gpg-agent

basically, it allows/forces your device to ask the password of the key

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