Unsetting git credential helper causes git submodule clone to fail

[jasjuang]

Setup

• Which version of Git for Windows are you using? Is it 32-bit or 64-bit?

$ git --version --build-options

16:03:24.278822 git.c:369               trace: built-in: git 'version' '--build-options'
git version 2.13.0.windows.1
built from commit: eba7af3dbb4c846c6303c5f64102acee696c9ab0
sizeof-long: 4
machine: x86_64

• Which version of Windows are you running? Vista, 7, 8, 10? Is it 32-bit or 64-bit?

$ cmd.exe /c ver

Microsoft Windows [Version 10.0.14393]

• What options did you set as part of the installation? Or did you choose the
  defaults?

# One of the following:
> type "C:\Program Files\Git\etc\install-options.txt"
> type "C:\Program Files (x86)\Git\etc\install-options.txt"
> type "%USERPROFILE%\AppData\Local\Programs\Git\etc\install-options.txt"
$ cat /etc/install-options.txt

Path Option: CmdTools
SSH Option: OpenSSH
CURL Option: OpenSSL
CRLF Option: LFOnly
Bash Terminal Option: MinTTY
Performance Tweaks FSCache: Enabled
Use Credential Manager: Disabled
Enable Symlinks: Disabled

Details

• Which terminal/shell are you running Git from? e.g Bash/CMD/PowerShell/other

CMD

I am on a shared windows machine with other people so the credentials won't be cached, so the below is executed to unset Git-Credential-Manager-for-Windows,

git config --global --unset credential.helper
git config --system --unset credential.helper

However, this causes a problem when I am cloning a repository that contains submodules, for example

git clone https://github.com/jasjuang/test  

This will prompt me to input username and password, and after I input them manually it successfully cloned all the non-submodule components, but, after I do

git submodule update --init --recursive

I get the error

bash: /dev/tty: No such device or address
error: failed to execute prompt script (exit code 1)
fatal: could not read Username for 'https://github.com': No error
fatal: clone of 'https://github.com/jasjunag/submoduletest' into submodule path 'C:/Users/Administrator/Desktop/test/external/submoduletest' failed

In linux, it will prompt me to input username and password again when cloning submodule, and after I input it everything will work fine. Why didn't Windows prompt me to enter the username and password again instead of just failing directly?

I filed an issue at GCM here microsoft/Git-Credential-Manager-for-Windows#434 but the maintainer suggested that this is a git for windows problem.

[dscho]

git clone https://github.com/jasjuang/test

This fails here, as I have no permissions to access that test.

I cannot spend more time on these credential tickets for now, as I already spent way too much time trying to recreate the problem in #1169.

If I had had working Minimal, Complete, Verifiable Examples to recreate the problem here, I could have spent that time working on a fix instead. Pity.

[jasjuang]

@dscho If I make that repository public so you can access it then that means everyone can access it without any credentials thus this problem can't be recreated. Making a minimal repository with a submodule in there to reproduce the problem should be very straightforward for someone who is maintaining a git for windows repository, but if you are having difficulties to recreate it let me figure out something. Is me providing you a detailed step-by-step guide on how to create a submodule easier or me creating a fake organization and add you into it so you would need to access the private repo with your credentials easier?

[jasjuang]

@dscho Here is the detailed step by step guide to create a repo with a submodule

0. Disable GCM

git config --global --unset credential.helper
git config --system --unset credential.helper

1. Create two public repositories on your github, first one name it test1, second one name it test2

2. Add one commits to each

git clone https://github.com/dscho/test1
cd test1
vim randomfile1

add some text into the file

git add randomfile1
git commit -a -m "first test1 commit"
git push origin master
cd ..

git clone https://github.com/dscho/test2
cd test2
vim randomfile2

add some text into the file

git add randomfile2
git commit -a -m "first test2 commit"
git push origin master
cd ..

3. Now both repos has commits on the master branches, it's time to add the submodules

cd test1
mkdir external
cd external
git submodule add -b master https://github.com/dscho/test2
git commit -a -m "submodule added"
git push origin master
cd ..

4. Go to github and make test1 and test2 private.

5. Now do a fresh clone and you will see the failure

rm -rf test1
rm -rf test2
git clone https://github.com/dscho/test1

It will prompt for your credentials and enter them, everything will run fine, but when you are cloning the submodule

cd test1
git submodule update --init --recursive

You will see exactly

bash: /dev/tty: No such device or address
error: failed to execute prompt script (exit code 1)
fatal: could not read Username for 'https://github.com': No error
fatal: clone of 'https://github.com/dscho/test2' into submodule path 'C:/Users/Administrator/Desktop/test1/external/test2' failed

Failed directly without prompting any credentials

6. Now turn on a linux machine, and you will see it works totally fine

git clone https://github.com/dscho/test1

It will prompt for your credentials and enter them, everything will run fine

cd test1
git submodule update --init --recursive

It will still prompt for your credentials and after you enter them everything will run fine.

Let me know if you need any additional instructions to reproduce the error, thanks.

[dscho]

the problem should be very straightforward for someone who is maintaining a git for windows repository, but if you are having difficulties to recreate it let me figure out something.

I simply do not have the time. There are 78 other tickets still open in this here bug tracker.

Unless I am mistaken, the superproject need not be a private one. Only the submodule does to force credentials. It can even point to a non-existing repository on GitHub, as GitHub will then assume it is a private one and ask for credentials.

Again, if I have to spend half an hour to set this up myself (or 5 minutes to write this answer), then that is time I cannot spend on working on a fix.

[jasjuang]

@dscho Understand that you are busy, we all appreciate your work. Please follow the above step by step guide to recreate the bug, it will take you no more than 3 minutes.

[AlmAck]

I had the same problem, I solved with this trick:
atom/atom#8984 (comment)

[jasjuang]

@AlmAck It didn't work for me. I manually added the below lines into the end of .git/config file

[credential]
    helper = wincred

and do a git submodule update --init --recursive the same error still occurs.

[dscho]

Please follow the above step by step guide to recreate the bug, it will take you no more than 3 minutes.

I am afraid that I really do not have those 3 minutes to spare.

[jasjuang]

Man, why are you so grumpy? Wouldn't it be more wise to use your time to recreate the bug instead of replying something like this? I tried my best to help on this issue. Understand this is open source so you have no obligation to fix this, but your attitude is very disappointing.

…

On Sat, Aug 5, 2017 at 1:46 PM Johannes Schindelin ***@***.***> wrote: Please follow the above step by step guide to recreate the bug, it will take you no more than 3 minutes. I am afraid that I *really* do not have those 3 minutes to spare. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#1191 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ALNuYNU5k1pL8DeIIfDRkguTmaFuLf-dks5sVNS8gaJpZM4NsTqE> .

[dscho]

@jasjuang you mistake my emotions. I usually try to help, and I like it when the same courtesy is extended to me, as it sometimes makes it possible for me to help. In this case, I can't help, which is a bit sad, but not the end of the world.

[re-schneider]

Hi,

I am glad to find this ticket as I was on my way to open the same one.

I have the same behavior with git for windows 2.14.2 and submodules where everything was fine with git for windows 2.8.x.
I always had my ~/.gitconfig defined to use the windows credentials helper:

[credential]
    helper = wincred

The only workaround I found is to:

• do a fresh clone of the parent repo
• edit the .gitmodules file to add my username in the url (https://foo.bar@server...)
• run the "git submodule init"
• run the "git submodule update --recursive --remote"
• revert the change with "git checkout -- .gitmodules"

The question is: was the 2.8.x the one with a happy bug (that was solved since) ? Or is it a regression introduced recently (maybe due to the git-credentials-manager shipped now in the pack and that seems to work according to some reports) ?

Sorry to pile-up an extra thing. If there is anything accessible that I can do to help narrow it down further to help with the investigation and fix, let me know :)

[kgybels]

I don't have a private repository. However, since GitHub will return a 404 when trying to access a private repository without credentials, we can also use a repository that does not exist. git submodule add won't work for such a repository, so we have to setup the submodule manually. I came up with the following to reproduce:

KGybels@PC-KIM MINGW64 /c/git/bug
$ git --version --build-options
git version 2.14.2.windows.1
built from commit: 788debdfb6b794425a3b949dd1a0eb2425a72e96
sizeof-long: 4
machine: x86_64

KGybels@PC-KIM MINGW64 /c/git/bug
$ ls -a
./  ../  steps.sh*

KGybels@PC-KIM MINGW64 /c/git/bug
$ cat ./steps.sh
#!/bin/bash

git init test
cd test
git config --file=.gitmodules submodule.test.path submodule
git config --file=.gitmodules submodule.test.url https://github.com/doesnot/exist
git config --file=.gitmodules submodule.test.branch master
git add .gitmodules
echo -e '160000 commit 0000000000000000000000000000000000000001\tsubmodule' | git update-index --index-info
git commit -m "Add submodule"
git -c credential.helper= submodule update --init --recursive

KGybels@PC-KIM MINGW64 /c/git/bug
$ ./steps.sh
Initialized empty Git repository in C:/git/bug/test/.git/
[master (root-commit) 4cee080] Add submodule
 2 files changed, 5 insertions(+)
 create mode 100644 .gitmodules
 create mode 160000 submodule
Submodule 'test' (https://github.com/doesnot/exist) registered for path 'submodule'
Cloning into 'C:/git/bug/test/submodule'...
bash: /dev/tty: No such device or address
error: failed to execute prompt script (exit code 1)
fatal: could not read Username for 'https://github.com': No error
fatal: clone of 'https://github.com/doesnot/exist' into submodule path 'C:/git/bug/test/submodule' failed
Failed to clone 'submodule'. Retry scheduled
Cloning into 'C:/git/bug/test/submodule'...
bash: /dev/tty: No such device or address
error: failed to execute prompt script (exit code 1)
fatal: could not read Username for 'https://github.com': No error
fatal: clone of 'https://github.com/doesnot/exist' into submodule path 'C:/git/bug/test/submodule' failed
Failed to clone 'submodule' a second time, aborting

KGybels@PC-KIM MINGW64 /c/git/bug
$

[kgybels]

@re-schneider Your workaround is very cumbersome indeed. You can specify the username in your configuration file instead:

[credential "https://example.com"]
	username = foo

You can find more information in the documention for gitcredentials.

[re-schneider]

@kgybels : thanks for the tip. Unfortunately, it may help with the workaround but makes no difference on an existing repo (same as adding the login to the .git/config or the .gitmodules).

[kgybels]

@re-schneider

Unfortunately, it may help with the workaround but makes no difference on an existing repo (same as adding the login to the .git/config or the .gitmodules).

I don't understand. Can you explain what the problem is?