Make asset map exception easier to debug

[oalders]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 73.13%. Comparing base (0615988) to head (1d3aab8).
Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
lib/MetaCPAN/Middleware/Static.pm	50.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3208      +/-   ##
==========================================
+ Coverage   73.12%   73.13%   +0.01%     
==========================================
  Files          69       69              
  Lines        2396     2397       +1     
  Branches      338      338              
==========================================
+ Hits         1752     1753       +1     
  Misses        517      517              
  Partials      127      127              

Files with missing lines	Coverage Δ
lib/MetaCPAN/Middleware/Static.pm	85.96% <50.00%> (+0.25%)	⬆️