17 Apr 2026
apogee_ntv Yeah the pain is real when the OS pager is involved. 14:07
Even then some OS's just ignore advisory flags (: 14:08
timo i wanted to just fuzz the parsing stage of the nqp compiler with afl, but of course afl stumbled upon the "constant" keyword and figured out how to generate invalid bytecode, specifically in a way that causes an exception while verifying the bytecode and leaving the default_allocate_gen2 level undecremented :) 17:33
Geth MoarVM/fix_gen2_default_sticking_after_bytecode_unpack_fail: dd72185ef1 | (Timo Paulssen)++ | src/core/bytecode.c
Clear gen2 default alloc flag when reporting erroneous bytecode

If an exception is thrown by any of the error cases when unpacking bytecode, we jump out of the function to run a handler which will not be prepared to deal with the gen2 flag being set (for example by having sp_fastcreate in it)
Found with afl++
19:13
MoarVM: timo++ created pull request #1998:
Clear gen2 default alloc flag when reporting erroneous bytecode
19:15
timo nqp: say("test") 19:20
18 Apr 2026
Geth MoarVM/main: 6b1fbd6cc1 | timo++ (committed using GitHub Web editor) | src/core/bytecode.c
Clear gen2 default alloc flag when reporting erroneous bytecode (#1998)

If an exception is thrown by any of the error cases when unpacking bytecode, we jump out of the function to run a handler which will not be prepared to deal with the gen2 flag being set (for example by having sp_fastcreate in it)
Found with afl++
12:29
MoarVM/main: c7365e7339 | timo++ (committed using GitHub Web editor) | src/strings/utf8_c8.c
utf8-c8: don't write past end of result buffer (#1994)
12:33
timo this is an important one
lizmat ok, will bump that one after I bumped Rakudo again... 12:36
so that we can bisect on these :-) 12:37
timo 'k 12:38
lizmat all bumped 12:51
timo good good 12:52
20 Apr 2026
patrickb when in the debugger I'm looking at a thread in the setting, the source code I can retrieve is the entire catted setting, the reported filename and line numbers are the ones of the originating files. Is it sane to cut the retrieved setting code up into it's original pieced and work with those? 08:39
lizmat Feels sane to me 09:27
21 Apr 2026
timo take cover behind something 14:31
Geth MoarVM/build_fuzzing_targets: 8 commits pushed by (Timo Paulssen)++
timo Geth: github.com/MoarVM/MoarVM/commit/f4...b32b8fd1ad 14:32
wasn't there a feature to give it a commit hash and have it spit out the commit log message like it would on a push of a single commit?
because I wrote quite a novel there :D
Geth: help
Geth timo, Source at github.com/Raku/geth To add repo, add an 'application/json' webhook on GitHub pointing it to webhooks.liz.nl/?chan=%23raku and choose 'Send me everything' for events to send | use `ver URL to commit` to fetch version bump changes
timo ok, not geth I guess. well, that's fine :) 14:33
Geth MoarVM/build_fuzzing_targets: edcee64e93 | (Timo Paulssen)++ | fuzzing/matches_no_functions.txt
fuzzing: Add "matches_no_functions.txt" helper for AFL_LLVM_ALLOWLIST
15:06
timo I also updated the description of github.com/MoarVM/MoarVM/pull/1996 a bunch 15:19
Geth MoarVM/build_fuzzing_targets: 544494608f | (Timo Paulssen)++ | build/Makefile.in
Add bb edge coverage obj and header to makefile
15:23
MoarVM/build_fuzzing_targets: dba926dc61 | (Timo Paulssen)++ | src/instrument/bb_edge_coverage.c
Fix MSVC compilation error regarding stpncpy
15:38
MoarVM/build_fuzzing_targets: 0450e40c33 | (Timo Paulssen)++ | 5 files
Move fuzzing related stuff into bb_edge_coverage files
16:33
librasteve_ rakudoweekly.blog/2026/04/21/2026-...framework/ 18:35
Geth MoarVM/build_fuzzing_targets: 804964dbae | (Timo Paulssen)++ | 5 files
Edge coverage filename output, change format to messagepack
21:29
MoarVM/build_fuzzing_targets: d043c6d639 | (Timo Paulssen)++ | tools/parse_edge_coverage.raku
use bb successors from BBIDX entries to show uncovered edges
22:22
22 Apr 2026
patrickb timo: In the current debugger impl, I'm essentially processing incoming events as a single stream of events. I rely on events not jumping the queue. This is made difficult by MVM-Remote splitting up incoming events into multiple streams. What's your opinion on adding a all-events supply that could be used alternatively? 05:46