Need help with E: Unable to locate package errors

Question

Why is it not able to locate the packages apt-get update && apt-get install -y --allow-unauthenticated \ libc6-dev \ libgdiplus \ libx11-dev \ && rm -rf /var/lib/apt/lists/*Reading package lists...Building dependency tree...Reading state information...E: Unable to locate package libc6-devE: Unable to locate package libgdiplusE: Unable to locate package libx11-devE: Unable to locate package

Phil Fitzgerald · Accepted Answer

It works when on the same line.  I guess the \ is not valid for line continuation in the yml.

- apt-get update && apt-get install -y --allow-unauthenticated libc6-dev libgdiplus libx11-dev && rm -rf /var/lib/apt/lists/*