My build is failing because of "No Such Key" or "Host key verification failed". What do I do?

If you are seeing these errors, your configuration is probably trying to use other repositories that Runnable does not have access to. 


To give containers within Runnable access to those dependency repositories, we just need to generate and add the right ssh key to the repository’s configuration:
  1. SSH keys come in a pair, private and public. To generate a new ssh key pair, open up a terminal session on a Linux or Mac machine you trust.
  2. Navigate to the ~/.ssh/ directory.
  3. Run the command ssh-keygen -t rsa -b 4096 -C "”.
  4. You will be prompted to provide a location for the generated key.
  5. Press enter if you are happy with the default location. You can change the location if you want to, but make sure that you choose a safe location.
  6. You will now be prompted to enter a passphrase. You have to press enter to signal that you don’t want to add a passphrase for this key. It's important to not set a paraphrase for the key to work with Runnable.
  7. You have now generated an ssh key pair. In our case, the private key is called  "id_rsa" and the public key is "".
  8. Now, you are ready to upload the public key to your user account.
  9. First copy the public key ( our case) to your clipboard.
  10. Next, log in to your account on
  11. Click on your username on the top right to reveal a tray.
  12. On the tray, click on “Settings”. 
  13. Next, click on “SSH Keys” settings under “Personal Settings”.
  14. Click on “New SSH Key” button on the top right. 
  15. Give your new ssh-key a title with which you can easily associate Runnable with.
  16. Paste the public key into the text area labeled “Key"
  17. Click on “Add SSH Key”.
  18. Now we move on to adding the private key into our repository configuration in Runnable.
  19. We first copy the private key we had generated in step 9.
  20. Navigate to the “Configure” page.
  21. Locate the repository that is failing to build.
  22. Click on the “Files & SSH Keys” tool.
  23. Click on the “Add…” dropdown.
  24. Select “SSH Key”.
  25. A modal will open with a label for "Title" and a text area titled "Key".
  26. Give your key a title that you can identify with.
  27. Paste in the private key that you copied in step 19 into the text area.
  28. Click "Save & Rebuild” and your failing build step should now complete successfully!


As always, please feel to reach out to us using the in-app chat if you are unable to resolve your build errors. 

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