From @AlexDaniel

See IRC log​: https://irclog.perlgeek.de/perl6-dev/2017-08-20#i_15045830

Some highlights from the log​:

Error​:
Unable to call postcircumfix $bt[ (Any) ] with a type object
Indexing requires a defined object
  in sub is_approx at /tmp/whateverable/rakudo-moar/10df9a95b3f5b4940fc7ce6b8ecf49fed0aea2f5/share/perl6/sources/C712FE6969F786C9380D643DF17E85D06868219E (Test) line 266
in block <unit> at /tmp/JRV8fruTHd line 87

Bisected to rakudo/rakudo@f590863

No issue with MVM_SPESH_DISABLE=1

From @AlexDaniel

A workaround for it was added in rakudo/rakudo@1d69ebb

Without MVM_SPESH_DISABLE=1 it can give this kind of warning​:

Block <unit> (from unknown) seen at​:
  /tmp/21S1e2RPQr, lines 107,115,122,69
Please use is-approx instead.

This is LTA but at least no longer critical.

On 2017-08-20 07​:06​:50, alex.jakimenko@​gmail.com wrote​:

See IRC log​: https://irclog.perlgeek.de/perl6-dev/2017-08-
20#i_15045830

Some highlights from the log​:

Error​:
Unable to call postcircumfix $bt[ (Any) ] with a type object
Indexing requires a defined object
in sub is_approx at /tmp/whateverable/rakudo-
moar/10df9a95b3f5b4940fc7ce6b8ecf49fed0aea2f5/share/perl6/sources/C712FE6969F786C9380D643DF17E85D06868219E
(Test) line 266
in block <unit> at /tmp/JRV8fruTHd line 87

Bisected to
rakudo/rakudo@f590863

No issue with MVM_SPESH_DISABLE=1