Better error on unknown concrete type

[vchuravy]

No description provided.

[codecov-commenter]

Codecov Report

Merging #290 (0b52c0d) into main (a7c1442) will decrease coverage by 0.53%.
The diff coverage is 25.00%.

@@            Coverage Diff             @@
##             main     #290      +/-   ##
==========================================
- Coverage   78.66%   78.12%   -0.54%     
==========================================
  Files          16       16              
  Lines        3224     3228       +4     
==========================================
- Hits         2536     2522      -14     
- Misses        688      706      +18     

Impacted Files	Coverage Δ
src/compiler.jl	79.40% <25.00%> (-0.12%)	⬇️
src/compiler/orcv2.jl	61.90% <0.00%> (-10.48%)	⬇️
src/compiler/orcv1.jl	76.92% <0.00%> (-3.85%)	⬇️
src/compiler/validation.jl	61.85% <0.00%> (-0.75%)	⬇️

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