Loading CombinedParsers causes segmentation fault

[KristofferC]

(@v1.8) pkg> st CombinedParsers
      Status `~/.julia/environments/v1.8/Project.toml`
  [5ae71ed2] CombinedParsers v0.1.6

julia> using CombinedParsers
[ Info: Precompiling CombinedParsers [5ae71ed2-6f8a-4ed1-b94f-e14e8158f19e]

signal (11): Segmentation fault
in expression starting at /home/kc/.julia/packages/CombinedParsers/ZoNay/src/re-parser.jl:229
sig_match_simple at /home/kc/julia/src/typemap.c:194 [inlined]
jl_typemap_entry_assoc_exact at /home/kc/julia/src/typemap.c:959
jl_typemap_assoc_exact at /home/kc/julia/src/julia_internal.h:1282 [inlined]
jl_lookup_generic_ at /home/kc/julia/src/gf.c:2367 [inlined]
jl_apply_generic at /home/kc/julia/src/gf.c:2423
jl_apply at /home/kc/julia/src/julia.h:1787 [inlined]
do_apply at /home/kc/julia/src/builtins.c:713
Either at /home/kc/.julia/packages/CombinedParsers/ZoNay/src/CombinedParsers.jl:2478
_jl_invoke at /home/kc/julia/src/gf.c:2226 [inlined]
jl_apply_generic at /home/kc/julia/src/gf.c:2427
jl_apply at /home/kc/julia/src/julia.h:1787 [inlined]
do_call at /home/kc/julia/src/interpreter.c:125
eval_value at /home/kc/julia/src/interpreter.c:214
eval_stmt_value at /home/kc/julia/src/interpreter.c:165 [inlined]
eval_body at /home/kc/julia/src/interpreter.c:583
jl_interpret_toplevel_thunk at /home/kc/julia/src/interpreter.c:727
jl_toplevel_eval_flex at /home/kc/julia/src/toplevel.c:885
jl_toplevel_eval_flex at /home/kc/julia/src/toplevel.c:830
jl_toplevel_eval_in at /home/kc/julia/src/toplevel.c:944
eval at ./boot.jl:373 [inlined]
include_string at ./loading.jl:1196
_jl_invoke at /home/kc/julia/src/gf.c:2226 [inlined]
jl_apply_generic at /home/kc/julia/src/gf.c:2427
_include at ./loading.jl:1253
include at ./Base.jl:417
_jl_invoke at /home/kc/julia/src/gf.c:2226 [inlined]
jl_apply_generic at /home/kc/julia/src/gf.c:2427
jl_apply at /home/kc/julia/src/julia.h:1787 [inlined]
jl_f__call_latest at /home/kc/julia/src/builtins.c:757
include at /home/kc/.julia/packages/CombinedParsers/ZoNay/src/re.jl:4
_jl_invoke at /home/kc/julia/src/gf.c:2226 [inlined]
jl_apply_generic at /home/kc/julia/src/gf.c:2427
jl_apply at /home/kc/julia/src/julia.h:1787 [inlined]
do_call at /home/kc/julia/src/interpreter.c:125
eval_value at /home/kc/julia/src/interpreter.c:214
eval_stmt_value at /home/kc/julia/src/interpreter.c:165 [inlined]
eval_body at /home/kc/julia/src/interpreter.c:583
jl_interpret_toplevel_thunk at /home/kc/julia/src/interpreter.c:727
jl_toplevel_eval_flex at /home/kc/julia/src/toplevel.c:885
jl_eval_module_expr at /home/kc/julia/src/toplevel.c:196 [inlined]
jl_toplevel_eval_flex at /home/kc/julia/src/toplevel.c:673
jl_toplevel_eval_flex at /home/kc/julia/src/toplevel.c:830
jl_toplevel_eval_flex at /home/kc/julia/src/toplevel.c:830
jl_toplevel_eval_in at /home/kc/julia/src/toplevel.c:944
eval at ./boot.jl:373 [inlined]
include_string at ./loading.jl:1196
_jl_invoke at /home/kc/julia/src/gf.c:2226 [inlined]
jl_apply_generic at /home/kc/julia/src/gf.c:2427
_include at ./loading.jl:1253
include at ./Base.jl:417
_jl_invoke at /home/kc/julia/src/gf.c:2226 [inlined]
jl_apply_generic at /home/kc/julia/src/gf.c:2427
jl_apply at /home/kc/julia/src/julia.h:1787 [inlined]
jl_f__call_latest at /home/kc/julia/src/builtins.c:757
include at /home/kc/.julia/packages/CombinedParsers/ZoNay/src/CombinedParsers.jl:13
_jl_invoke at /home/kc/julia/src/gf.c:2226 [inlined]
jl_apply_generic at /home/kc/julia/src/gf.c:2427
jl_apply at /home/kc/julia/src/julia.h:1787 [inlined]
do_call at /home/kc/julia/src/interpreter.c:125
eval_value at /home/kc/julia/src/interpreter.c:214
eval_stmt_value at /home/kc/julia/src/interpreter.c:165 [inlined]
eval_body at /home/kc/julia/src/interpreter.c:583
jl_interpret_toplevel_thunk at /home/kc/julia/src/interpreter.c:727
jl_toplevel_eval_flex at /home/kc/julia/src/toplevel.c:885
jl_eval_module_expr at /home/kc/julia/src/toplevel.c:196 [inlined]
jl_toplevel_eval_flex at /home/kc/julia/src/toplevel.c:673
jl_toplevel_eval_flex at /home/kc/julia/src/toplevel.c:830
jl_toplevel_eval_flex at /home/kc/julia/src/toplevel.c:830
jl_toplevel_eval_in at /home/kc/julia/src/toplevel.c:944
eval at ./boot.jl:373 [inlined]
include_string at ./loading.jl:1196
_jl_invoke at /home/kc/julia/src/gf.c:2226 [inlined]
jl_apply_generic at /home/kc/julia/src/gf.c:2427
_include at ./loading.jl:1253
include at ./Base.jl:417 [inlined]
include_package_for_output at ./loading.jl:1318
jfptr_include_package_for_output_25692 at /home/kc/julia/usr/lib/julia/sys.so (unknown line)
_jl_invoke at /home/kc/julia/src/gf.c:2226 [inlined]
jl_apply_generic at /home/kc/julia/src/gf.c:2427
jl_apply at /home/kc/julia/src/julia.h:1787 [inlined]
do_call at /home/kc/julia/src/interpreter.c:125
eval_value at /home/kc/julia/src/interpreter.c:214
eval_stmt_value at /home/kc/julia/src/interpreter.c:165 [inlined]
eval_body at /home/kc/julia/src/interpreter.c:583
jl_interpret_toplevel_thunk at /home/kc/julia/src/interpreter.c:727
jl_toplevel_eval_flex at /home/kc/julia/src/toplevel.c:885
jl_toplevel_eval_in at /home/kc/julia/src/toplevel.c:944
eval at ./boot.jl:373 [inlined]
eval at ./client.jl:453
_jl_invoke at /home/kc/julia/src/gf.c:2226 [inlined]
jl_apply_generic at /home/kc/julia/src/gf.c:2427
jl_apply at /home/kc/julia/src/julia.h:1787 [inlined]
do_call at /home/kc/julia/src/interpreter.c:125
eval_value at /home/kc/julia/src/interpreter.c:214
eval_stmt_value at /home/kc/julia/src/interpreter.c:165 [inlined]
eval_body at /home/kc/julia/src/interpreter.c:583
jl_interpret_toplevel_thunk at /home/kc/julia/src/interpreter.c:727
jl_toplevel_eval_flex at /home/kc/julia/src/toplevel.c:885
jl_toplevel_eval_flex at /home/kc/julia/src/toplevel.c:830
jl_toplevel_eval_in at /home/kc/julia/src/toplevel.c:944
eval at ./boot.jl:373 [inlined]
exec_options at ./client.jl:268
_start at ./client.jl:495
jfptr__start_36699 at /home/kc/julia/usr/lib/julia/sys.so (unknown line)
_jl_invoke at /home/kc/julia/src/gf.c:2226 [inlined]
jl_apply_generic at /home/kc/julia/src/gf.c:2427
jl_apply at /home/kc/julia/src/julia.h:1787 [inlined]
true_main at /home/kc/julia/src/jlapi.c:559
jl_repl_entrypoint at /home/kc/julia/src/jlapi.c:701
main at /home/kc/julia/cli/loader_exe.c:42
__libc_start_main at /lib/x86_64-linux-gnu/libc.so.6 (unknown line)
_start at /home/kc/julia/usr/bin/julia (unknown line)
Allocations: 23490256 (Pool: 23483914; Big: 6342); GC: 27
ERROR: Failed to precompile CombinedParsers [5ae71ed2-6f8a-4ed1-b94f-e14e8158f19e] to /home/kc/.julia/compiled/v1.8/CombinedParsers/jl_BHWuJB.

This regression was found when testing #41499 against :release-1.7 which means that the offending commit is among the ones in #41499.

[JeffBezanson]

We are getting a null reference from a tuple whose first element is

Base.Pair{Char, CombinedParsers.AtStart}(first=Char(0x41000000), second=#<null>)

Clearly that should not be possible; there might be some layout disagreement somewhere.

[JeffBezanson]

Ah, this is AtStart:

struct AtStart <: NIndexParser{0,AtStart} end