From @LLFourn

This happens a lot at the moment. The issue has been around pre-curli but I
think precompilation has exposed it a lot. So I'm making this ticket to
focus on the general issue

1. Happens a lot in panda
==> Bootstrapping Panda
Use of uninitialized value %ENV of type Any in string context
Any of .^name, .perl, .gist, or .say can stringify undefined things, if
needed. in sub MAIN at bootstrap.pl​:12
Use of uninitialized value %ENV of type Any in string context
...
==> Fetching Linenoise
Use of uninitialized value %ENV of type Any in string context
Any of .^name, .perl, .gist, or .say can stringify undefined things, if
needed. in sub git-fetch at
/Users/llfourn/.rakudobrew/moar-nom/install/share/perl6/site/sources/66302B2E45F3ADCA25D8D7CCEF34037ECE91C096​:46

2. Bug #​126447 for perl6​: [BUG] temp %*ENV bug
https://rt.perl.org/Public/Bug/Display.html?id=126447

3. Bug #​126840 for perl6​: $*KERNEL and env lookup
https://rt.perl.org/Public/Bug/Display.html?id=126840

4. Bug #​126880 for perl6​: [BUG] no precompilation with compile time warning
dies painfully
https://rt.perl.org/Public/Bug/Display.html?id=126880

It happens in CLONE-HASH-DECONTAINERIZED in core/control.pm, when %*ENV is
cloned (usually in preparation for shelling out some command in qx// or
something) when it has some dubious value.

https://github.com/rakudo/rakudo/blob/nom/src/core/control.pm#L267

The particular value related to precompilation that causes it
is RAKUDO_PRECOMP_DIST