Stream 'dump.gcdump' is in an unknown or unsupported file format.

[JSGInray]

After creating a dump using
dotnet gcdump collect
In a docker container it can't be opened using clrmd.
However the same dump can be opened in visual studio.

[wnayes]

A gcdump is a special kind of heap dump that only certain tools understand, like PerfView.

I am pretty sure ClrMD only supports "lower level" memory dumps that contain raw .NET memory, such as those created by dotnet dump.