Compiler AssertionError(msg="found nested Conditional")

[krynju]

This is a non-critical error not affecting correctness found in nightly CI runs and on local test runs using master.
I can probably get an MWE easily later this week, but right now running the test suite of either packages does well at reproducing it every run.

Found in:

• Dagger.jl https://buildkite.com/julialang/dagger-dot-jl/builds/605#018245c3-efe0-4b65-970e-c5f02d4d758f
• DTables.jl https://github.com/JuliaParallel/DTables.jl/runs/7565532424?check_suite_focus=true

Locally I'm getting it on a ~2 month old build:

julia> versioninfo()
Julia Version 1.9.0-DEV.706
Commit bd8dbc388c (2022-06-02 21:46 UTC)

Error:

Internal error: encountered unexpected error in runtime:
AssertionError(msg="found nested conditional")
assert_nested_type at .\compiler\typelattice.jl:139 [inlined]
Conditional at .\compiler\typelattice.jl:50 [inlined]
Conditional at .\compiler\typelattice.jl:54 [inlined]
abstract_call_builtin at .\compiler\abstractinterpretation.jl:1484
abstract_call_known at .\compiler\abstractinterpretation.jl:1637
abstract_call at .\compiler\abstractinterpretation.jl:1797
abstract_call at .\compiler\abstractinterpretation.jl:1762
abstract_eval_statement at .\compiler\abstractinterpretation.jl:1918
abstract_eval_basic_statement at .\compiler\abstractinterpretation.jl:2272
typeinf_local at .\compiler\abstractinterpretation.jl:2449
typeinf_nocycle at .\compiler\abstractinterpretation.jl:2547
_typeinf at .\compiler\typeinfer.jl:230
typeinf at .\compiler\typeinfer.jl:213
typeinf_ext at .\compiler\typeinfer.jl:1031
typeinf_ext_toplevel at .\compiler\typeinfer.jl:1064
typeinf_ext_toplevel at .\compiler\typeinfer.jl:1060
jfptr_typeinf_ext_toplevel_15238 at C:\cygwin64\home\krynjupc\julia\usr\lib\julia\sys.dll (unknown line)
_jl_invoke at /home/krynjupc/julia/src\gf.c:2392 [inlined]
ijl_apply_generic at /home/krynjupc/julia/src\gf.c:2574 [inlined]
jl_apply at /home/krynjupc/julia/src\julia.h:1841 [inlined]
jl_type_infer at /home/krynjupc/julia/src\gf.c:317
jl_generate_fptr_impl at /home/krynjupc/julia/src\jitlayers.cpp:344
jl_compile_method_internal at /home/krynjupc/julia/src\gf.c:2106
jl_compile_method_internal at /home/krynjupc/julia/src\gf.c:2050 [inlined]
_jl_invoke at /home/krynjupc/julia/src\gf.c:2384 [inlined]
ijl_apply_generic at /home/krynjupc/julia/src\gf.c:2574
walk_data at C:\Users\krynjupc\.julia\dev\Dagger\src\sch\util.jl:421
walk_storage_safe at C:\Users\krynjupc\.julia\dev\Dagger\src\sch\util.jl:470 [inlined]
do_task at C:\Users\krynjupc\.julia\dev\Dagger\src\sch\Sch.jl:1142
macro expansion at C:\Users\krynjupc\.julia\dev\Dagger\src\sch\Sch.jl:956 [inlined]
#121 at .\task.jl:499
unknown function (ip: 00000000640c4153)
jl_apply at /home/krynjupc/julia/src\julia.h:1841 [inlined]
start_task at /home/krynjupc/julia/src\task.c:931

cc: @jpsamaroo

[aviatesk]

Thanks for reporting this issue! This is exactly what I wanted to have when adding the assertions.