wslc doesn't strip \r in << redirection

[jdbruner]

Windows Version

Microsoft Windows [Version 10.0.26300.8758]

WSL Version

wslc 2.9.3.0

Are you using WSL 1 or WSL 2?

• WSL 2
• WSL 1

Kernel Version

No response

Distro Version

No response

Other Software

No response

Repro Steps

1. Create a Dockerfile that uses <<xxx redirection in a RUN command and is in DOS file format (i.e., lines are terminated with \r\n)

FROM docker.io/library/debian:trixie
RUN <<EOF
set -e
touch /tmp/foo
EOF

[This is not a contrived example. Git for Windows will typically extract text files with \r\n line endings.]

2. Attempt to build it using wslc build .

Expected Behavior

It should build successfully:

PS> wslc build -f Dockerfile.test .
Building image from directory: .

[1/2] FROM docker.io/library/debian:trixie
[2/2] RUN <<EOF (set -e...)
exporting to image
  | exporting layers
  | writing image sha256:8c80c334792040128709827780e6d1d294d6d2df127d7c23ad7e9b0446752cc4

Actual Behavior

The build fails because the command to sh in the Debian image includes carriage returns:

PS> wslc build -f Dockerfile.test .
Building image from directory: .

[1/2] FROM docker.io/library/debian:trixie
[2/2] RUN <<EOF (set -e...)
process "/bin/sh -c set -e\r\ntouch /tmp/foo\r\n" did not complete successfully: exit code: 2
  | /bin/sh: 1: set: Illegal option -
Dockerfile:2
--------------------
   1 |     FROM docker.io/library/debian:trixie
   2 | >>> RUN <<EOF
   3 | >>> set -e
   4 | >>> touch /tmp/foo
   5 | >>> EOF
   6 |
--------------------
ERROR: failed to solve: process "/bin/sh -c set -e\r\ntouch /tmp/foo\r\n" did not complete successfully: exit code: 2

Error code: E_FAIL

Diagnostic Logs

WslLogs-2026-07-04_14-45-53.tar.gz

[github-actions]

Logs are required for review from WSL team

If this a feature request, please reply with '/feature'. If this is a question, reply with '/question'.
Otherwise, please attach logs by following the instructions below, your issue will not be reviewed unless they are added. These logs will help us understand what is going on in your machine.

How to collect WSL logs

Download and execute collect-wsl-logs.ps1 in an administrative powershell prompt:

Invoke-WebRequest -UseBasicParsing "https://raw.githubusercontent.com/microsoft/WSL/master/diagnostics/collect-wsl-logs.ps1" -OutFile collect-wsl-logs.ps1
Set-ExecutionPolicy Bypass -Scope Process -Force
.\collect-wsl-logs.ps1

The script will output the path of the log file once done.

If this is a networking issue, please use .\collect-wsl-logs.ps1 -LogProfile networking instead, following the instructions in Collect WSL logs for networking issues

Once completed please upload the output files to this GitHub issue.

See Collect WSL logs (recommended method).

If you choose to email these logs instead of attaching them to the bug, please send them to wsl-gh-logs@microsoft.com with the GitHub issue number in the subject, and include a link to your GitHub issue comment in the message body, and reply with '/emailed-logs'.

[github-actions]

Diagnostic information

Issue was edited and new log file was found: https://github.com/user-attachments/files/29665735/WslLogs-2026-07-04_14-45-53.tar.gz
Detected appx version: 2.9.3.0