Error piping on docker

[giggio]

Versions

ConEmu build: x64
ConEmu version: 16.10.22.0
OS version: Windows 10 x64 (Version 1607 OS Build 14393.447)
Used shell version (Far Manager, git-bash, cmd, powershell, cygwin, whatever): ???

Problem description

When using Docker for Windows, while using Linux containers, if you run on Conemu:

And PowerShell:

 echo 'FROM hello-world' | docker build -t temp -

or

'FROM hello-world' | docker build -t temp -

Or on cmd:

echo FROM hello-world | docker build -t temp -

You get this error:

unable to prepare context: failed to peek context header from STDIN: Incorrect function.

This is NOT an error with Docker, the command works on cmd and PowerShell without Conemu.

Docker version:

C:\>docker version
Client:
 Version:      1.12.3
 API version:  1.24
 Go version:   go1.6.3
 Git commit:   6b644ec
 Built:        Thu Oct 27 00:09:21 2016
 OS/Arch:      windows/amd64
 Experimental: true

Server:
 Version:      1.12.3
 API version:  1.24
 Go version:   go1.6.3
 Git commit:   6b644ec
 Built:        Thu Oct 27 00:09:21 2016
 OS/Arch:      linux/amd64
 Experimental: true

Steps to reproduce

1. Type the command:

echo 'FROM hello-world' | docker build -t temp -

Actual results

unable to prepare context: failed to peek context header from STDIN: Incorrect function.

Expected results

Docker run without errors

[Maximus5]

Please report this top Docker team
Third-party application problems

[giggio]

This is not an error on the docker client. The error only happens when the command runs in Conemu. It does not happen on plain PowerShell or plain CMD. It is clearly an error in Conemu.

[Maximus5]

It would be an error in ConEmu, if Docker acts absolutely the same way in ConEmu as in raw conhost.
But it does not!
Brief look into issues will prove that!
Docker true to determine ConEmu presence and behave differently.
Again. Report to the Docker's team.

[friism]

@giggio

• https://github.com/docker/docker/blob/28cca5dcaa2aa21123805d7f2d51916ea1f38d71/pkg/term/term_windows.go#L74
• Force input stream ANSI emulation for ConEmu. moby/moby#25578

[giggio]

Ok, so Docker is screwing up. I am closing the issue and opening another one there.

[giggio]

Opened moby/moby#28814, so anyone with the same error can follow up.

[sergluka]

As a workaround, disabling ConEmu Settings -> Features -> ANSI and xterm sequences helped me.