[CN] Crash when logging SMT output with --solver-logging

[septract]

CN crashes with too many open files when logging SMT output using --solver-logging.

Replication

Test file open_files_minimized.c (generated from @cp526's pagetable code by creduce):

enum a { b, c, d };
long e() {}
long f() { long g; }
void h(enum a i, long j) {
  _Bool device = i & d;
  int k = device ? 4 : 0, l, ap = 0 ? 1 : 3;
  long attr = 0 << 0 << 0 >> 0 >> 0;
  if (i & c)
    ;
  attr |= 0;
}

Output:

$ cn verify --solver-logging=blah open_files_minimized.c
cn verify --solver-logging=blah open_files_minimized.c
[1/3]: e -- fail
[2/3]: f -- fail
[3/3]: h -- pass
open_files_minimized.c:2:1: error: Undefined behaviour
long e() {}
~~~~~^~~~~~
the value of a non-void function that ended without a return statement is used
State file: file:///var/folders/sl/2lpz4lb10ylbnbzqplt1bjj00000gp/T/state__open_files_minimized.c__e.html
cn: internal error, uncaught exception:
    Sys_error("/var/folders/sl/2lpz4lb10ylbnbzqplt1bjj00000gp/T/state__open_files_minimized.c__f.html: Too many open files")
    Raised by primitive operation at Stdlib.open_out_gen in file "stdlib.ml", line 329, characters 29-55
    Called from Stdlib.open_out in file "stdlib.ml" (inlined), line 334, characters 2-74
    Called from Cn__Report.make in file "backend/cn/lib/report.ml", line 814, characters 11-28
    Called from Cn__TypeErrors.report_pretty in file "backend/cn/lib/typeErrors.ml", line 638, characters 17-72
    Called from Stdlib__List.iter in file "list.ml", line 110, characters 12-15
    Called from Dune__exe__Main.verify.(fun).check in file "backend/cn/bin/main.ml", line 339, characters 10-242
    Called from Cn__Typing.run_from_pause in file "backend/cn/lib/typing.ml", line 68, characters 50-55
    Called from Dune__exe__Main.with_well_formedness_check in file "backend/cn/bin/main.ml", line 164, characters 6-573
    Re-raised at Dune__exe__Main.with_well_formedness_check in file "backend/cn/bin/main.ml", line 186, characters 4-69
    Called from Cmdliner_term.app.(fun) in file "cmdliner_term.ml", line 24, characters 19-24
    Called from Cmdliner_eval.run_parser in file "cmdliner_eval.ml", line 35, characters 37-44

CN version: git-ba4a38312 [2025-02-13 16:43:44 -0500]

For some reason, this bug does not occur when I call CN through the embedded shell in VS Code. This seems totally bizarre to me - I have no idea what's going on.