What exactly does "restricted to versions 1.0.0 by an explicit requirement" mean?

Mattriks May 2, 2019, 10:28pm 2

There’s another example here
with an explanation in this post

Topic		Replies	Views
Impenetrable error message General Usage package	12	437	May 5, 2022
Compatibility issues: How to read the error? General Usage	3	845	July 12, 2019
Solving "restricted by julia compatibility requirements to versions: uninstalled — no versions left" New to Julia	3	3307	September 26, 2019
"ERROR: Unsatisfiable requirements detected for..." how to understand this? New to Julia	1	1424	May 13, 2019
Understanding an "Unsatisfiable requirements" problems General Usage question , pkg	9	984	April 24, 2019