'error ENDOFLINE: Fix end of line marker.' in CI but not locally

• DevOps
• .NET
• C#

In a previous article we explored how we can enforce code style in a solution with dotnet format --verify-no-changes.

Today we are discussing a rule that can be enabled in the .eidtorconfig file and potentially interfere with your local git settings so that dotnet format fails in the CI build but produces no errors locally.

The problem

dotnet format will use a set of default rules, however, we can customize it with .editorconfig file inside our solution and enable additional validations.

One of the rules we can enable is New Line under New line preferences in the Whitespace configuration section.

It, as you may already know, allows us to enforce a line ending. The options are:

• Newline (\\n)
• Carriage Return (\r)
• Carriage Return + Newline (\r\n)

Windows uses the default ending of Carriage Return + Newline \r\n aka CRLF, whereas Unix-based systems prefer Newline \\n aka line feed - LF.

Git for Windows allows automatic replacement of Windows-like CRLF endings with Unix-default LF, and, if the setting is enabled, Git does it on each checkin and checkout. It means that locally you always have CRLF endings, but remote repos have Unix-friendly LF.

With Carriage Return + Newline (\r\n) option enabled in .editorconfig and CRLF -> LF automatic replacement in Git, dotnet format --verify-no-changes succeeds locally, but fails in a CI build with this error:

error ENDOFLINE: Fix end of line marker. Replace 2 characters with '\r\n\r\n'.

If you remember that Git can silently change the endings, the error is quite straightforward, otherwise it may be very confusing since you cannot reproduce it locally.

The fix

Of course, you can just disable Git CRLF -> LF replacement, but it doesn’t solve the problem for other people working on the same project.

So a better approach would be modifying the .gitattributes file in your root folder, which will tell Git the line endings we expect in the repo. Add the following line in your .gitattributes file:

* text eol=crlf

This will tell Git that we are using CRLF endings for all text files and it will not try to replace it with LF for this repo.

Summary

• Git end-of-line (eol) conversion can interfere with .editorconfig New Line rule.
• dotnet format --verify-no-changes can fail with error ENDOFLINE: Fix end of line marker. Replace 2 characters with '\r\n\r\n'. error in a CI build but succeed locally if Git eol conversion is enabled.
• We can instruct Git to respect CRLF endings in .gitattributes which will enforce it for everyone on the team.
• Keep your line endings synchronized between .gitattributes and .editorconfig.
• Read more about .gitattributes file.
• Read why Windows uses CRLF as the default ending.