OK, so I think I’ve found what happens.
You are using version 3.0.2 of G’MIC, and there was a name change for value type in the .gmz and .cimgz that has been introduced in G’MIC 3.1.0.
Excerpt from the changelog:
* *[core-310]* Names of pixel types have been normalized. Now, they can be `{ bool | uint8 | int8 | uint16 | int16 | uint32 | int32 | uint64 | int64 | float32 | float64 }`.
In particular, pixel type uint8 replaces old uchar, and float32 replaces old float.
These new names are used in the header of the file gmic_denoise_cnn.gmz because this file has been updated since 3.1.0, and while newer versions of G’MIC are able to read .gmz files with the older type names, the contrary is not true.
I’m then a bit sorry to say this, but you won’t be able to run command denoise_cnn with G’MIC 3.0.2.
Could it be a good occasion for the packagers of Solus to update G’MIC to the latest stable version 3.2.3 ?