Try another approach in echo'ing

.appveyor.yml

@@ -24,19 +24,19 @@ install:
         Where-Object pullRequestId -eq $env:APPVEYOR_PULL_REQUEST_NUMBER)[0].buildNumber) { `
           throw "There are newer queued builds for this pull request, failing early." }
 
-  - ECHO OS version:
+  - cmd: echo "OS version:"
   - ps: "[System.Environment]::OSVersion.Version"
 
-  - ECHO Filesystem root:
+  - cmd: echo "Filesystem root:"
   - ps: "ls \"C:\\\""
 
-  - ECHO Filesystem projects root:
+  - cmd: echo "Filesystem projects root:"
   - ps: "ls \"C:\\projects\\\""
 
-  - ECHO Filesystem pyfa root:
+  - cmd: echo "Filesystem pyfa root:"
   - ps: "ls \"C:\\projects\\$env:APPVEYOR_PROJECT_SLUG\\\""
 
-  - ECHO Installed SDKs:
+  - cmd: echo "Installed SDKs:"
   - ps: "ls \"C:\\Program Files (x86)\\Windows Kits\\\""
 
   # Prepend newly installed Python to the PATH of this build (this cannot be
@@ -55,7 +55,7 @@ install:
   # compiled extensions and are not provided as pre-built wheel packages,
   # pip will build them from source using the MSVC compiler matching the
   # target Python version and architecture
-  - ECHO "Install pip requirements:"
+  - cmd: echo "Install pip requirements:"
   - "python -m pip install -r requirements.txt"
   - "python -m pip install PyInstaller==3.6"
 
@@ -67,7 +67,7 @@ before_build:
   - ps: echo ($env:PYFA_VERSION)
 
 build_script:
-  - ECHO "Build pyfa:"
+  - cmd: echo "Build pyfa:"
 
   # Build gamedata DB
   - "python db_update.py"