Tom Tromey [Fri, 23 Apr 2021 17:28:48 +0000 (11:28 -0600)]
Fix crash when expanding partial symtabs with DW_TAG_imported_unit
PR gdb/27743 points out a gdb crash when expanding partial symtabs,
where one of the compilation units uses DW_TAG_imported_unit.
The bug is that partial_map_expand_apply expects only to be called for
the outermost psymtab. However, filename searching doesn't (and
probably shouldn't) guarantee this. The fix is to walk upward to find
the outermost CU.
A new test case is included. It is mostly copied from other test
cases, which really sped up the effort.
This bug does not occur on trunk. There,
psym_map_symtabs_matching_filename is gone, replaced by
psymbol_functions::expand_symtabs_matching. When this find a match,
it calls psymtab_to_symtab, which does this same upward walk.
Tested on x86-64 Fedora 32.
I propose checking in this patch on the gdb-10 branch, and just the
new test case on trunk.
gdb/ChangeLog
2021-04-23 Tom Tromey <tromey@adacore.com>
gdb/testsuite/ChangeLog
2021-04-23 Tom Tromey <tromey@adacore.com>
PR gdb/27743:
* gdb.dwarf2/imported-unit-bp.exp: New file.
* gdb.dwarf2/imported-unit-bp-main.c: New file.
* gdb.dwarf2/imported-unit-bp-alt.c: New file.
Simon Marchi [Thu, 22 Apr 2021 19:05:18 +0000 (15:05 -0400)]
gdb: fix getting range of flexible array member in Python
As reported in bug 27757, we get an internal error when doing:
$ cat test.c
struct foo {
int len;
int items[];
};
struct foo *p;
int main() {
return 0;
}
$ gcc test.c -g -O0 -o test
$ ./gdb -q -nx --data-directory=data-directory ./test -ex 'python gdb.parse_and_eval("p").type.target()["items"].type.range()'
Reading symbols from ./test...
/home/simark/src/binutils-gdb/gdb/gdbtypes.h:435: internal-error: LONGEST dynamic_prop::const_val() const: Assertion `m_kind == PROP_CONST' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
This is because the Python code (typy_range) blindly reads the high
bound of the type of `items` as a constant value. Since it is a
flexible array member, it has no high bound, the property is undefined.
Since commit 8c2e4e0689 ("gdb: add accessors to struct dynamic_prop"),
the getters check that you are not getting a property value of the wrong
kind, so this causes a failed assertion.
Fix it by checking if the property is indeed a constant value before
accessing it as such. Otherwise, use 0. This restores the previous GDB
behavior: because the structure was zero-initialized, this is what was
returned before. But now this behavior is explicit and not accidental.
Add a test, gdb.python/flexible-array-member.exp, that is derived from
gdb.base/flexible-array-member.exp. It tests the same things, but
through the Python API. It also specifically tests getting the range
from the various kinds of flexible array member types (AFAIK it wasn't
possible to do the equivalent through the CLI).
gdb/ChangeLog:
PR gdb/27757
* python/py-type.c (typy_range): Check that bounds are constant
before accessing them as such.
* guile/scm-type.c (gdbscm_type_range): Likewise.
gdb/testsuite/ChangeLog:
PR gdb/27757
* gdb.python/flexible-array-member.c: New test.
* gdb.python/flexible-array-member.exp: New test.
* gdb.guile/scm-type.exp (test_range): Add test for flexible
array member.
* gdb.guile/scm-type.c (struct flex_member): New.
(main): Use it.
This is a recurring problem that exposes a design issue in the DWARF
per-BFD sharing feature. Things work well when loading a binary with
the same method (with/without index, with/without readnow) twice in a
row. But they don't work so well when loading a binary with different
methods. See this previous fix, for example:
efb763a5ea35 ("gdb: check for partial symtab presence in dwarf2_initialize_objfile")
That one handled the case where the first load is normal (uses partial
symbols) and the second load uses an index.
The problem is that when loading an objfile with a method A, we create a
dwarf2_per_bfd and some dwarf2_per_cu_data and initialize them with the
data belonging to that method. When loading another obfile sharing the
same BFD but with a different method B, it's not clear how to re-use the
dwarf2_per_bfd/dwarf2_per_cu_data previously created, because they
contain the data specific to method A.
I think the most sensible fix would be to not share a dwarf2_per_bfd
between two objfiles loaded with different methods. That means that two
objfiles sharing the same BFD and loaded the same way would share a
dwarf2_per_bfd. Two objfiles sharing the same BFD but loaded with
different methods would use two different dwarf2_per_bfd structures.
However, this isn't a trivial change. So to fix the known issue quickly
(including in the gdb 10 branch), this patch just disables all
dwarf2_per_bfd sharing for objfiles using READNOW.
Generalize the gdb.base/index-cache-load-twice.exp test to test all
the possible combinations of loading a file with partial symtabs, index
and readnow. Move it to gdb.dwarf2, since it really exercises features
of the DWARF reader.
gdb/ChangeLog:
PR gdb/27541
* dwarf2/read.c (dwarf2_has_info): Don't share dwarf2_per_bfd
with objfiles using READNOW.
This avoids using a thread-local extern variable, which causes link errors
on some platforms, notably Cygwin. But I think this is a better pattern
even outside of working around linker bugs because it encapsulates direct
access to the variable inside the class, instead of having a global extern
variable.
The cygwin link error is:
cp-support.o: in function `gdb_demangle(char const*, int)':
/home/Christian/binutils-gdb/obj/gdb/../../gdb/cp-support.c:1619:(.text+0x6472): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `TLS init function for thread_local_segv_handler'
/home/Christian/binutils-gdb/obj/gdb/../../gdb/cp-support.c:1619:(.text+0x648b): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `TLS init function for thread_local_segv_handler'
collect2: error: ld returned 1 exit status
2021-03-12 Christian Biesinger <cbiesinger@google.com>
PR threads/27239
* cp-support.c: Use scoped_segv_handler_restore.
* event-top.c (thread_local_segv_handler): Made static.
(scoped_segv_handler_restore::scoped_segv_handler_restore):
New function.
(scoped_segv_handler_restore::~scoped_segv_handler_restore): New
function.
* event-top.h (class scoped_segv_handler_restore): New class.
(thread_local_segv_handler): Removed.
Tom de Vries [Sun, 7 Mar 2021 16:58:28 +0000 (17:58 +0100)]
[gdb/symtab] Fix element type modification in read_array_type
When running test-case gdb.fortran/function-calls.exp with target board
unix/gdb:debug_flags=-gdwarf-5, I run into:
...
(gdb) PASS: gdb.fortran/function-calls.exp: \
p derived_types_and_module_calls::pass_cart(c)
p derived_types_and_module_calls::pass_cart_nd(c_nd)^M
^M
Program received signal SIGSEGV, Segmentation fault.^M
0x0000000000400f73 in derived_types_and_module_calls::pass_cart_nd \
(c=<error reading variable: Cannot access memory at address 0xc>) at \
function-calls.f90:130^M
130 pass_cart_nd = ubound(c%d,1,4)^M
The program being debugged was signaled while in a function called from GDB.^M
GDB has restored the context to what it was before the call.^M
To change this behavior use "set unwindonsignal off".^M
Evaluation of the expression containing the function^M
(derived_types_and_module_calls::pass_cart_nd) will be abandoned.^M
(gdb) FAIL: gdb.fortran/function-calls.exp: p
...
The problem originates in read_array_type, when reading a DW_TAG_array_type
with a dwarf-5 DW_TAG_generic_subrange child. This is not supported, and the
fallout of this is that rather than constructing a new array type, the code
proceeds to modify the element type.
Fix this conservatively by issuing a complaint and bailing out in
read_array_type when not being able to construct an array type, such that we
have:
...
(gdb) maint expand-symtabs function-calls.f90^M
During symbol reading: unable to find array range \
- DIE at 0xe1e [in module function-calls]^M
During symbol reading: unable to find array range \
- DIE at 0xe1e [in module function-calls]^M
(gdb) KFAIL: gdb.fortran/function-calls.exp: no complaints in srcfile \
(PRMS: symtab/27388)
...
Tested on x86_64-linux.
gdb/ChangeLog:
2021-03-07 Tom de Vries <tdevries@suse.de>
PR symtab/27341
* dwarf2/read.c (read_array_type): Return NULL when not being able to
construct an array type. Add assert to ensure that element_type is
not being modified.
gdb/testsuite/ChangeLog:
2021-03-07 Tom de Vries <tdevries@suse.de>
PR symtab/27341
* lib/gdb.exp (with_complaints): New proc, factored out of ...
(gdb_load_no_complaints): ... here.
* gdb.fortran/function-calls.exp: Add test-case.
Kevin Buettner [Wed, 24 Feb 2021 18:48:04 +0000 (11:48 -0700)]
Fix aarch64-linux-hw-point.c build problem
Due to a recent glibc header file change, the file
nat/aarch64-linux-hw-point.c no longer builds on Fedora rawhide.
An enum for PTRACE_SYSEMU is now provided by <sys/ptrace.h>. In the
past, PTRACE_SYSEMU was defined only in <asm/ptrace.h>. This is
what it looks like...
When <asm/ptrace.h> and <sys/ptrace.h> are both included in a source
file, we run into the following build problem when the former is
included before the latter:
In file included from nat/aarch64-linux-hw-point.c:26:
/usr/include/sys/ptrace.h:86:3: error: expected identifier before numeric constant
86 | PTRACE_SYSEMU = 31,
| ^~~~~~~~~~~~~
(There are more errors after this one too.)
The file builds without error when <asm/ptrace.h> is included after
<sys/ptrace.h>. I found that this is already done in
nat/aarch64-sve-linux-ptrace.h (which is included by
nat/aarch64-linux-ptrace.c).
I've tested this change on Fedora rawhide and Fedora 33, both
running on an aarch64 machine.
gdb/ChangeLog:
PR build/27536
* nat/aarch64-linux-hw-point.c: Include <asm/ptrace.h> after
<sys/ptrace.h>.
Kevin Buettner [Fri, 19 Feb 2021 05:46:58 +0000 (22:46 -0700)]
amd64-linux-siginfo.c: Adjust include order to avoid gnulib error
On Fedora rawhide, after updating to glibc-2.33, I'm seeing the
following build failure:
CXX nat/amd64-linux-siginfo.o
In file included from /usr/include/bits/sigstksz.h:24,
from /usr/include/signal.h:315,
from ../gnulib/import/signal.h:52,
from /ironwood1/sourceware-git/rawhide-gnulib/bld/../../worktree-gnulib/gdbserver/../gdb/nat/amd64-linux-siginfo.c:20:
../gnulib/import/unistd.h:663:3: error: #error "Please include config.h first."
663 | #error "Please include config.h first."
| ^~~~~
glibc-2.33 has changed signal.h to now include <bits/sigstksz.h> which,
in turn, includes <unistd.h>. For a gdb build, this causes the gnulib
version of unistd.h to be pulled in first. The build failure shown
above happens because gnulib's config.h has not been included before
the include of <signal.h>.
The fix is simple - we just rearrange the order of the header file
includes to make sure that gdbsupport/commondefs.h is included before
attempting to include signal.h. Note that gdbsupport/commondefs.h
includes <gnulib/config.h>.
Build and regression tested on Fedora 33. On Fedora rawhide, GDB
builds again.
gdb/ChangeLog:
PR build/27535
* nat/amd64-linux-siginfo.c: Include "gdbsupport/common-defs.h"
(which in turn includes <gnulib/config.h>) before include
of <signal.h>.
Tom de Vries [Fri, 5 Feb 2021 16:47:07 +0000 (17:47 +0100)]
[gdb/symtab] Handle DW_TAG_type_unit in process_psymtab_comp_unit
When running test-case gdb.cp/cpexprs-debug-types.exp with target board
unix/gdb:debug_flags=-gdwarf-5, I run into:
...
(gdb) file cpexprs-debug-types^M
Reading symbols from cpexprs-debug-types...^M
ERROR: Couldn't load cpexprs-debug-types into GDB (eof).
ERROR: Couldn't send delete breakpoints to GDB.
ERROR: GDB process no longer exists
GDB process exited with wait status 23054 exp9 0 0 CHILDKILLED SIGABRT SIGABRT
...
We're running into this abort in process_psymtab_comp_unit:
...
switch (reader.comp_unit_die->tag)
{
case DW_TAG_compile_unit:
this_cu->unit_type = DW_UT_compile;
break;
case DW_TAG_partial_unit:
this_cu->unit_type = DW_UT_partial;
break;
default:
abort ();
}
...
because reader.comp_unit_die->tag == DW_TAG_type_unit.
Simon Marchi [Thu, 4 Mar 2021 15:57:03 +0000 (10:57 -0500)]
gdb: set current thread in sparc_{fetch,collect}_inferior_registers (PR gdb/27147)
PR 27147 shows that on sparc64, GDB is unable to properly unwind:
Expected result (from GDB 9.2):
#0 0x0000000000108de4 in puts ()
#1 0x0000000000100950 in hello () at gdb-test.c:4
#2 0x0000000000100968 in main () at gdb-test.c:8
Actual result (from GDB latest git):
#0 0x0000000000108de4 in puts ()
#1 0x0000000000100950 in hello () at gdb-test.c:4
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
The first failing commit is 5b6d1e4fa4fc ("Multi-target support"). The cause
of the change in behavior is due to (thanks for Andrew Burgess for finding
this):
- inferior_ptid is no longer set on entry of target_ops::wait, whereas
it was set to something valid previously
- deep down in linux_nat_target::wait (see stack trace below), we fetch
the registers of the event thread
- on sparc64, fetching registers involves reading memory (in
sparc_supply_rwindow, see stack trace below)
- reading memory (target_ops::xfer_partial) relies on inferior_ptid
being set to the thread from which we want to read memory
This is where things go wrong:
#0 linux_nat_target::xfer_partial (this=0x10000fa2c40 <the_sparc64_linux_nat_target>, object=TARGET_OBJECT_MEMORY, annex=0x0, readbuf=0x7feffe3b000 "", writebuf=0x0, offset=8791798050744, len=8, xfered_len=0x7feffe3ae88) at /home/simark/src/binutils-gdb/gdb/linux-nat.c:3697
#1 0x00000100007f5b10 in raw_memory_xfer_partial (ops=0x10000fa2c40 <the_sparc64_linux_nat_target>, readbuf=0x7feffe3b000 "", writebuf=0x0, memaddr=8791798050744, len=8, xfered_len=0x7feffe3ae88) at /home/simark/src/binutils-gdb/gdb/target.c:912
#2 0x00000100007f60e8 in memory_xfer_partial_1 (ops=0x10000fa2c40 <the_sparc64_linux_nat_target>, object=TARGET_OBJECT_MEMORY, readbuf=0x7feffe3b000 "", writebuf=0x0, memaddr=8791798050744, len=8, xfered_len=0x7feffe3ae88) at /home/simark/src/binutils-gdb/gdb/target.c:1043
#3 0x00000100007f61b4 in memory_xfer_partial (ops=0x10000fa2c40 <the_sparc64_linux_nat_target>, object=TARGET_OBJECT_MEMORY, readbuf=0x7feffe3b000 "", writebuf=0x0, memaddr=8791798050744, len=8, xfered_len=0x7feffe3ae88) at /home/simark/src/binutils-gdb/gdb/target.c:1072
#4 0x00000100007f6538 in target_xfer_partial (ops=0x10000fa2c40 <the_sparc64_linux_nat_target>, object=TARGET_OBJECT_MEMORY, annex=0x0, readbuf=0x7feffe3b000 "", writebuf=0x0, offset=8791798050744, len=8, xfered_len=0x7feffe3ae88) at /home/simark/src/binutils-gdb/gdb/target.c:1129
#5 0x00000100007f7094 in target_read_partial (ops=0x10000fa2c40 <the_sparc64_linux_nat_target>, object=TARGET_OBJECT_MEMORY, annex=0x0, buf=0x7feffe3b000 "", offset=8791798050744, len=8, xfered_len=0x7feffe3ae88) at /home/simark/src/binutils-gdb/gdb/target.c:1375
#6 0x00000100007f721c in target_read (ops=0x10000fa2c40 <the_sparc64_linux_nat_target>, object=TARGET_OBJECT_MEMORY, annex=0x0, buf=0x7feffe3b000 "", offset=8791798050744, len=8) at /home/simark/src/binutils-gdb/gdb/target.c:1415
#7 0x00000100007f69d4 in target_read_memory (memaddr=8791798050744, myaddr=0x7feffe3b000 "", len=8) at /home/simark/src/binutils-gdb/gdb/target.c:1218
#8 0x0000010000758520 in sparc_supply_rwindow (regcache=0x10000fea4f0, sp=8791798050736, regnum=-1) at /home/simark/src/binutils-gdb/gdb/sparc-tdep.c:1960
#9 0x000001000076208c in sparc64_supply_gregset (gregmap=0x10000be3190 <sparc64_linux_ptrace_gregmap>, regcache=0x10000fea4f0, regnum=-1, gregs=0x7feffe3b230) at /home/simark/src/binutils-gdb/gdb/sparc64-tdep.c:1974
#10 0x0000010000751b64 in sparc_fetch_inferior_registers (regcache=0x10000fea4f0, regnum=80) at /home/simark/src/binutils-gdb/gdb/sparc-nat.c:170
#11 0x0000010000759d68 in sparc64_linux_nat_target::fetch_registers (this=0x10000fa2c40 <the_sparc64_linux_nat_target>, regcache=0x10000fea4f0, regnum=80) at /home/simark/src/binutils-gdb/gdb/sparc64-linux-nat.c:38
#12 0x00000100008146ec in target_fetch_registers (regcache=0x10000fea4f0, regno=80) at /home/simark/src/binutils-gdb/gdb/target.c:3287
#13 0x00000100006a8c5c in regcache::raw_update (this=0x10000fea4f0, regnum=80) at /home/simark/src/binutils-gdb/gdb/regcache.c:584
#14 0x00000100006a8d94 in readable_regcache::raw_read (this=0x10000fea4f0, regnum=80, buf=0x7feffe3b7c0 "") at /home/simark/src/binutils-gdb/gdb/regcache.c:598
#15 0x00000100006a93b8 in readable_regcache::cooked_read (this=0x10000fea4f0, regnum=80, buf=0x7feffe3b7c0 "") at /home/simark/src/binutils-gdb/gdb/regcache.c:690
#16 0x00000100006b288c in readable_regcache::cooked_read<unsigned long, void> (this=0x10000fea4f0, regnum=80, val=0x7feffe3b948) at /home/simark/src/binutils-gdb/gdb/regcache.c:777
#17 0x00000100006a9b44 in regcache_cooked_read_unsigned (regcache=0x10000fea4f0, regnum=80, val=0x7feffe3b948) at /home/simark/src/binutils-gdb/gdb/regcache.c:791
#18 0x00000100006abf3c in regcache_read_pc (regcache=0x10000fea4f0) at /home/simark/src/binutils-gdb/gdb/regcache.c:1295
#19 0x0000010000507920 in save_stop_reason (lp=0x10000fc5b10) at /home/simark/src/binutils-gdb/gdb/linux-nat.c:2612
#20 0x00000100005095a4 in linux_nat_filter_event (lwpid=520983, status=1407) at /home/simark/src/binutils-gdb/gdb/linux-nat.c:3050
#21 0x0000010000509f9c in linux_nat_wait_1 (ptid=..., ourstatus=0x7feffe3c8f0, target_options=...) at /home/simark/src/binutils-gdb/gdb/linux-nat.c:3194
#22 0x000001000050b1d0 in linux_nat_target::wait (this=0x10000fa2c40 <the_sparc64_linux_nat_target>, ptid=..., ourstatus=0x7feffe3c8f0, target_options=...) at /home/simark/src/binutils-gdb/gdb/linux-nat.c:3432
#23 0x00000100007f8ac0 in target_wait (ptid=..., status=0x7feffe3c8f0, options=...) at /home/simark/src/binutils-gdb/gdb/target.c:2000
#24 0x00000100004ac17c in do_target_wait_1 (inf=0x1000116d280, ptid=..., status=0x7feffe3c8f0, options=...) at /home/simark/src/binutils-gdb/gdb/infrun.c:3464
#25 0x00000100004ac3b8 in operator() (__closure=0x7feffe3c678, inf=0x1000116d280) at /home/simark/src/binutils-gdb/gdb/infrun.c:3527
#26 0x00000100004ac7cc in do_target_wait (wait_ptid=..., ecs=0x7feffe3c8c8, options=...) at /home/simark/src/binutils-gdb/gdb/infrun.c:3540
#27 0x00000100004ad8c4 in fetch_inferior_event () at /home/simark/src/binutils-gdb/gdb/infrun.c:3880
#28 0x0000010000485568 in inferior_event_handler (event_type=INF_REG_EVENT) at /home/simark/src/binutils-gdb/gdb/inf-loop.c:42
#29 0x000001000050d394 in handle_target_event (error=0, client_data=0x0) at /home/simark/src/binutils-gdb/gdb/linux-nat.c:4060
#30 0x0000010000ab5c8c in handle_file_event (file_ptr=0x10001207270, ready_mask=1) at /home/simark/src/binutils-gdb/gdbsupport/event-loop.cc:575
#31 0x0000010000ab6334 in gdb_wait_for_event (block=0) at /home/simark/src/binutils-gdb/gdbsupport/event-loop.cc:701
#32 0x0000010000ab487c in gdb_do_one_event () at /home/simark/src/binutils-gdb/gdbsupport/event-loop.cc:212
#33 0x0000010000542668 in start_event_loop () at /home/simark/src/binutils-gdb/gdb/main.c:348
#34 0x000001000054287c in captured_command_loop () at /home/simark/src/binutils-gdb/gdb/main.c:408
#35 0x0000010000544e84 in captured_main (data=0x7feffe3d188) at /home/simark/src/binutils-gdb/gdb/main.c:1242
#36 0x0000010000544f2c in gdb_main (args=0x7feffe3d188) at /home/simark/src/binutils-gdb/gdb/main.c:1257
#37 0x00000100000c1f14 in main (argc=4, argv=0x7feffe3d548) at /home/simark/src/binutils-gdb/gdb/gdb.c:32
There is a target_read_memory call in sparc_supply_rwindow, whose return
value is not checked. That call fails, because inferior_ptid does not
contain a valid ptid, and uninitialized buffer contents is used.
Ultimately it results in a corrupt stop_pc.
target_ops::fetch_registers can be (and should remain, in my opinion)
independent of inferior_ptid, because the ptid of the thread from which
to fetch registers can be obtained from the regcache. In other words,
implementations of target_ops::fetch_registers should not rely on
inferior_ptid having a sensible value on entry.
The sparc64_linux_nat_target::fetch_registers case is special, because it calls
a target method that is dependent on the inferior_ptid value
(target_read_inferior, and ultimately target_ops::xfer_partial). So I would
say it's the responsibility of sparc64_linux_nat_target::fetch_registers to set
up inferior_ptid correctly prior to calling target_read_inferior.
This patch makes sparc64_linux_nat_target::fetch_registers (and
store_registers, since it works the same) temporarily set inferior_ptid. If we
ever make target_ops::xfer_partial independent of inferior_ptid, setting
inferior_ptid won't be necessary, we'll simply pass down the ptid as a
parameter in some way.
I chose to set/restore inferior_ptid in sparc_fetch_inferior_registers, because
I am not convinced that doing so in an inner location (in sparc_supply_rwindow
for instance) would always be correct. We have access to the ptid in
sparc_supply_rwindow (from the regcache), so we _could_ set inferior_ptid
there. However, I don't want to just set inferior_ptid, as that would make it
not desync'ed with `current_thread ()` and `current_inferior ()`. It's
preferable to use switch_to_thread instead, as that switches all the global
"current" stuff in a coherent way. But doing so requires a `thread_info *`,
and getting a `thread_info *` from a ptid requires a `process_stratum_target
*`. We could use `current_inferior()->process_target()` in
sparc_supply_rwindow for this (using target_read_memory uses the current
inferior's target stack anyway). However, sparc_supply_rwindow is also used in
the context of BSD uthreads, where a thread stratum target defines threads. I
presume the ptid in the regcache would be the ptid of the uthread, defined by
the thread stratum target (bsd_uthread_target). Using
`current_inferior()->process_target()` would look up a ptid defined by the
thread stratum target using the process stratum target. I don't think it would
give good results. So I prefer playing it safe and looking up the thread
earlier, in sparc_fetch_inferior_registers.
I added some assertions (in sparc_supply_rwindow and others) to verify
that the regcache's ptid matches inferior_ptid. That verifies that the
caller has properly set the correct global context. This would have
caught (though a failed assertion) the current problem.