Studio animators have been facing crashes with overrides of complex characters, when saving .blend file, after an override resync.
**Blender Version**
Broken: version: 2.90.1, version: 2.92.0 Alpha, branch: master, commit date: 2020-10-22 10:41, hash: rBdea3b8d9844f
Worked: 2.82a (but there is no chain icon on the armature data block, so perhaps it was not even linked back then), 2.83.8 LTS
**Short description of error**
Blender crashes using make local on an armature of a linked collection with library override.
It does not crash under a certain condition: if you save the file after step 4) below, then revert the file, *don't* click the armature again (it's already active), just continue at step 5) it will not crash.
Reset to factory defaults did not prevent the crash.
**Exact steps for others to reproduce the error**
# Create a collection with e.g. a rigify human meta rig, add some mesh and parent it with automatic weights (might be unnecessary), save file.
# Create a new file, link the collection from the original file
# Object - Relations - Make Library Override
# Select Rig
# In the object data properties of the armature, click the chain icon to make local
# Crash
Here is a backtrace from @pablico :
```lines=20
Thread 21 "blender" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffc163a700 (LWP 232709)]
pose_channel_in_IK_chain (ob=0x7fffab331408, pchan=0x7fffb64f9808, level=0)
at /media/data/blender_guest/blender_master/source/blender/blenkernel/intern/action.c:912
912 for (bone = pchan->bone->childbase.first; bone; bone = bone->next) {
#0 pose_channel_in_IK_chain (ob=0x7fffab331408, pchan=0x7fffb64f9808, level=0)
at /media/data/blender_guest/blender_master/source/blender/blenkernel/intern/action.c:912
#1 0x000000000379aff2 in BKE_pose_channel_in_IK_chain
(ob=0x7fffab331408, pchan=0x7fffb64f9808)
at /media/data/blender_guest/blender_master/source/blender/blenkernel/intern/action.c:923
#2 0x00000000040acdc6 in rna_PoseChannel_has_ik_get (ptr=0x7fffc15df170)
at /media/data/blender_guest/blender_master/source/blender/makesrna/intern/rna_pose.c:327
#3 0x00000000040b088f in PoseBone_is_in_ik_chain_get (ptr=0x7fffc15df170)
at /media/data/blender_guest/cmake_debug/source/blender/makesrna/intern/rna_pose_gen.c:1059
--Type <RET> for more, q to quit, c to continue without paging--c
#4 0x0000000003f40f1d in RNA_property_boolean_get (ptr=0x7fffc15df170, prop=0x132f9b40 <rna_PoseBone_is_in_ik_chain>) at /media/data/blender_guest/blender_master/source/blender/makesrna/intern/rna_access.c:2340
#5 0x00000000040bea8d in rna_property_override_diff_default (bmain=0x7fffb9b8ad08, prop_a=0x7fffc15df170, prop_b=0x7fffc15df1b0, mode=0, override=0x7fffab344568, rna_path=0x7fffc15df2b0 "pose.bones[\"ORG-HeelPivot.R\"].is_in_ik_chain", rna_path_len=44, flags=131072, r_override_changed=0x7fffc15df08d) at /media/data/blender_guest/blender_master/source/blender/makesrna/intern/rna_rna.c:1534
#6 0x0000000003f523ec in rna_property_override_diff (bmain=0x7fffb9b8ad08, prop_a=0x7fffc15df170, prop_b=0x7fffc15df1b0, rna_path=0x7fffc15df2b0 "pose.bones[\"ORG-HeelPivot.R\"].is_in_ik_chain", rna_path_len=44, mode=RNA_EQ_STRICT, override=0x7fffab344568, flags=(RNA_OVERRIDE_COMPARE_CREATE | RNA_OVERRIDE_COMPARE_RESTORE), r_report_flags=0x7fffc15df128) at /media/data/blender_guest/blender_master/source/blender/makesrna/intern/rna_access_compare_override.c:344
#7 0x0000000003f53037 in RNA_struct_override_matches (bmain=0x7fffb9b8ad08, ptr_local=0x7fffc15e5598, ptr_reference=0x7fffc15e5628, root_path=0x7fffc15e1380 "pose.bones[\"ORG-HeelPivot.R\"]", root_path_len=29, override=0x7fffab344568, flags=(RNA_OVERRIDE_COMPARE_CREATE | RNA_OVERRIDE_COMPARE_RESTORE), r_report_flags=0x7fffc15e133c) at /media/data/blender_guest/blender_master/source/blender/makesrna/intern/rna_access_compare_override.c:704
#8 0x00000000040be5d5 in rna_property_override_diff_propptr (bmain=0x7fffb9b8ad08, propptr_a=0x7fffc15e5598, propptr_b=0x7fffc15e5628, mode=RNA_EQ_STRICT, no_ownership=false, no_prop_name=false, override=0x7fffab344568, rna_path=0x7fffc15e8a00 "pose.bones", rna_path_len=10, property_type=6, rna_itemname_a=0x7fffc15e5750 "ORG-HeelPivot.R", rna_itemname_b=0x7fffc15e7750 "ORG-HeelPivot.R", rna_itemindex_a=10, rna_itemindex_b=10, flags=196608, r_override_changed=0x7fffc15e87dd) at /media/data/blender_guest/blender_master/source/blender/makesrna/intern/rna_rna.c:1419
#9 0x00000000040bf95f in rna_property_override_diff_default (bmain=0x7fffb9b8ad08, prop_a=0x7fffc15e88c0, prop_b=0x7fffc15e8900, mode=0, override=0x7fffab344568, rna_path=0x7fffc15e8a00 "pose.bones", rna_path_len=10, flags=196608, r_override_changed=0x7fffc15e87dd) at /media/data/blender_guest/blender_master/source/blender/makesrna/intern/rna_rna.c:1897
#10 0x0000000003f523ec in rna_property_override_diff (bmain=0x7fffb9b8ad08, prop_a=0x7fffc15e88c0, prop_b=0x7fffc15e8900, rna_path=0x7fffc15e8a00 "pose.bones", rna_path_len=10, mode=RNA_EQ_STRICT, override=0x7fffab344568, flags=(RNA_OVERRIDE_COMPARE_CREATE | RNA_OVERRIDE_COMPARE_RESTORE), r_report_flags=0x7fffc15e8878) at /media/data/blender_guest/blender_master/source/blender/makesrna/intern/rna_access_compare_override.c:344
#11 0x0000000003f53037 in RNA_struct_override_matches (bmain=0x7fffb9b8ad08, ptr_local=0x7fffc15eec80, ptr_reference=0x7fffc15eed10, root_path=0x7fffc0a476f8 "pose", root_path_len=4, override=0x7fffab344568, flags=(RNA_OVERRIDE_COMPARE_CREATE | RNA_OVERRIDE_COMPARE_RESTORE), r_report_flags=0x7fffc15eaa8c) at /media/data/blender_guest/blender_master/source/blender/makesrna/intern/rna_access_compare_override.c:704
#12 0x00000000040be5d5 in rna_property_override_diff_propptr (bmain=0x7fffb9b8ad08, propptr_a=0x7fffc15eec80, propptr_b=0x7fffc15eed10, mode=RNA_EQ_STRICT, no_ownership=false, no_prop_name=false, override=0x7fffab344568, rna_path=0x7fffc0a476f8 "pose", rna_path_len=4, property_type=5, rna_itemname_a=0x0, rna_itemname_b=0x0, rna_itemindex_a=-1, rna_itemindex_b=-1, flags=196608, r_override_changed=0x7fffc15f1f2d) at /media/data/blender_guest/blender_master/source/blender/makesrna/intern/rna_rna.c:1419
#13 0x00000000040bf4ff in rna_property_override_diff_default (bmain=0x7fffb9b8ad08, prop_a=0x7fffc15f2010, prop_b=0x7fffc15f2050, mode=0, override=0x7fffab344568, rna_path=0x7fffc0a476f8 "pose", rna_path_len=4, flags=196608, r_override_changed=0x7fffc15f1f2d) at /media/data/blender_guest/blender_master/source/blender/makesrna/intern/rna_rna.c:1743
#14 0x0000000003f523ec in rna_property_override_diff (bmain=0x7fffb9b8ad08, prop_a=0x7fffc15f2010, prop_b=0x7fffc15f2050, rna_path=0x7fffc0a476f8 "pose", rna_path_len=4, mode=RNA_EQ_STRICT, override=0x7fffab344568, flags=(RNA_OVERRIDE_COMPARE_CREATE | RNA_OVERRIDE_COMPARE_RESTORE), r_report_flags=0x7fffc15f1fc8) at /media/data/blender_guest/blender_master/source/blender/makesrna/intern/rna_access_compare_override.c:344
#15 0x0000000003f53037 in RNA_struct_override_matches (bmain=0x7fffb9b8ad08, ptr_local=0x7fffc15f41a0, ptr_reference=0x7fffc15f41c0, root_path=0x0, root_path_len=0, override=0x7fffab344568, flags=(RNA_OVERRIDE_COMPARE_CREATE | RNA_OVERRIDE_COMPARE_RESTORE), r_report_flags=0x7fffc15f4194) at /media/data/blender_guest/blender_master/source/blender/makesrna/intern/rna_access_compare_override.c:704
#16 0x000000000332f67c in BKE_lib_override_library_operations_create (bmain=0x7fffb9b8ad08, local=0x7fffab331408) at /media/data/blender_guest/blender_master/source/blender/blenkernel/intern/lib_override.c:1371
#17 0x000000000332f74d in lib_override_library_operations_create_cb (pool=0x7fffaee48708, taskdata=0x7fffab331408) at /media/data/blender_guest/blender_master/source/blender/blenkernel/intern/lib_override.c:1402
#18 0x000000000df8f238 in Task::operator()() const::{lambda()#1}::operator()() const (__closure=0x7fffc15f4310) at /media/data/blender_guest/blender_master/source/blender/blenlib/intern/task_pool.cc:118
#19 0x000000000df8f6b8 in tbb::interface7::internal::delegated_function<Task::operator()() const::{lambda()#1} const, void>::operator()() const (this=0x7fffc15f42a0) at /media/data/blender_guest/lib/linux_centos7_x86_64/tbb/include/tbb/task_arena.h:93
#20 0x0000000003876c85 in tbb::interface7::internal::isolate_within_arena(tbb::interface7::internal::delegate_base&, long) ()
#21 0x000000000df8f43d in tbb::interface7::internal::isolate_impl<void, Task::operator()() const::{lambda()#1} const>(Task::operator()() const::{lambda()#1} const&) (f=...) at /media/data/blender_guest/lib/linux_centos7_x86_64/tbb/include/tbb/task_arena.h:160
#22 0x000000000df8f343 in tbb::interface7::this_task_arena::isolate<Task::operator()() const::{lambda()#1}>(tbb::interface7::internal::return_type_or_void const&) (f=...) at /media/data/blender_guest/lib/linux_centos7_x86_64/tbb/include/tbb/task_arena.h:395
#23 0x000000000df8f26f in Task::operator()() const (this=0x7fffb9c26ec8) at /media/data/blender_guest/blender_master/source/blender/blenlib/intern/task_pool.cc:118
#24 0x000000000df8f690 in tbb::internal::function_task<Task>::execute() (this=0x7fffb9c26ec0) at /media/data/blender_guest/lib/linux_centos7_x86_64/tbb/include/tbb/task.h:1048
#25 0x0000000003884385 in tbb::internal::custom_scheduler<tbb::internal::IntelSchedulerTraits>::process_bypass_loop(tbb::internal::context_guard_helper<false>&, tbb::task*, long) ()
#26 0x000000000388463b in tbb::internal::custom_scheduler<tbb::internal::IntelSchedulerTraits>::local_wait_for_all(tbb::task&, tbb::task*) ()
#27 0x0000000003876997 in tbb::internal::arena::process(tbb::internal::generic_scheduler&) ()
#28 0x000000000387e100 in tbb::internal::market::process(rml::job&) ()
#29 0x000000000388010c in tbb::internal::rml::private_worker::run() ()
#30 0x0000000003880309 in tbb::internal::rml::private_worker::thread_routine(void*) ()
#31 0x00007ffff7f8f609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#32 0x00007ffff796f103 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
```
This seems to point again to some pose data not being up-to-date...
---
//Slightly different steps leading to the same issue, this is fixed now in master.//
**Blender Version**
Broken: version: 2.90.1, version: 2.92.0 Alpha, branch: master, commit date: 2020-10-22 10:41, hash: rBdea3b8d9844f
Worked: 2.82a (but there is no chain icon on the armature data block, so perhaps it was not even linked back then), 2.83.8 LTS
**Short description of error**
Blender crashes using make local on an armature of a linked collection with library override.
It does not crash under a certain condition: if you save the file after step 4) below, then revert the file, *don't* click the armature again (it's already active), just continue at step 5) it will not crash.
Reset to factory defaults did not prevent the crash.
**Exact steps for others to reproduce the error**
# Create a collection with e.g. a rigify human meta rig, add some mesh and parent it with automatic weights (might be unnecessary), save file.
# Create a new file, link the collection from the original file
# Object - Relations - Make Library Override
# Select Rig
# In the object data properties of the armature, click the chain icon to make local
# Crash