From @AlexDaniel

Code​:
Blob[num32].new(2e0) # huh?

¦«2015.12»​:
This type cannot unbox to a native integer
  in any at gen/moar/m-Metamodel.nqp line 1718
  in block <unit> at /home/bisectable/git/whateverable/data/regressionable/15265198/snippet line 1
«exit code = 1»

¦«2016.06»​:
Could not instantiate role 'Blob'​:
Blobs with native num32 not yet implemented. Sorry.
  in any at gen/moar/m-Metamodel.nqp line 2437
  in any specialize at gen/moar/m-Metamodel.nqp line 2424
  in any specialize at gen/moar/m-Metamodel.nqp line 2634
  in any specialize at gen/moar/m-Metamodel.nqp line 2212
  in any compose at gen/moar/m-Metamodel.nqp line 2993
  in any make_pun at gen/moar/m-Metamodel.nqp line 1701
  in any find_method at gen/moar/m-Metamodel.nqp line 1729
  in block <unit> at /home/bisectable/git/whateverable/data/regressionable/15265198/snippet line 1
«exit code = 1»

¦«2016.12»​:
Could not instantiate role 'Blob'​:
Blobs with native num32 not yet implemented. Sorry.
  in any at gen/moar/Metamodel.nqp line 2441
  in any protect at gen/moar/stage2/NQPCORE.setting line 802
  in any specialize at gen/moar/Metamodel.nqp line 2428
  in any specialize at gen/moar/Metamodel.nqp line 2644
  in any specialize at gen/moar/Metamodel.nqp line 2211
  in any compose at gen/moar/Metamodel.nqp line 3010
  in any make_pun at gen/moar/Metamodel.nqp line 1692
  in any find_method at gen/moar/Metamodel.nqp line 1720
  in block <unit> at /home/bisectable/git/whateverable/data/regressionable/15265198/snippet line 1
«exit code = 1»

¦«2017.06»​:
Could not instantiate role 'Blob'​:
Blobs with native num32 not yet implemented. Sorry.
  in any protect at gen/moar/stage2/NQPCORE.setting line 1029
  in block <unit> at /home/bisectable/git/whateverable/data/regressionable/15265198/snippet line 1
«exit code = 1»

¦«f72be0f130cf»​:
concatenate requires a concrete string, but got null
  in any protect at gen/moar/stage2/NQPCORE.setting line 1039
  in block <unit> at /home/bisectable/git/whateverable/data/regressionable/15265198/snippet line 1
«exit code = 1»

Possible IRC discussion​: https://irclog.perlgeek.de/perl6-dev/2017-10-06#i_15265198
Bisectable​: (2017-07-08) rakudo/rakudo@1a4d949

I think that the previous message is right​:

Could not instantiate role 'Blob'​:
Blobs with native num32 not yet implemented. Sorry.

And this message is wrong (or LTA if you wish)​:

concatenate requires a concrete string, but got null

From @zoffixznet

MasterDuke++ fixed in rakudo/rakudo@f4f3691

testneeded

From @MasterDuke17

Fixed in rakudo/rakudo#1189

Not sure where tests should go, roast or rakudo?

The RT System itself - Status changed from 'new' to 'open'

From @zoffixznet

Tests in rakudo/rakudo@e475ae8

@zoffixznet - Status changed from 'open' to 'resolved'