A few days ago, I started seeing some odd failures in one of my Azure DevOps Pipeline YAML builds. The error was:

/azure-pipelines.yml (Line: 1, Col: 1): Unexpected value 'name'

The beginning of the file looked like:

name: $(Build.BuildId)
pool: Default

 - master

After looking through the documentation repeatedly, a clue arose when doing a git diff. The output was:

diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 3fda759..4ece8de 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -1,5 +1,5 @@
+<U+FEFF>name: $(Build.BuildId)
-name: $(Build.BuildId)

<U+FEFF>?! Someone/something had snuck a byte order mark (BOM) into the beginning of my pipeline file! It turns out that certain text editors in Windows environments will inject this character at the beginning a file.

Once this was identified as the problem, the solution in this case utilized Visual Studio Code. In the bottom right corner on the window, a piece of information listed is the file encoding. The encoding listed for this file was UTF-8 with BOM. Clicking on the encoding opens the Command Palette and presents options. Selecting either Save with Encoding or Reopen with Encoding and then saving the file gets rid of the offending character.

After that change was committed and pushed, the build succeeded.