Commandline:

/tank/emaste/src/freebsd-xlld/tools_bin/ld \
--sysroot=/tank/emaste/obj/tank/emaste/src/freebsd-xlld/tmp -Bstatic -o as /tank/emaste/obj/tank/emaste/src/freebsd-xlld/tmp/usr/lib/crt1.o /tank/emaste/obj/tank/emaste/src/freebsd-xlld/tmp/usr/lib/crti.o /tank/emaste/obj/tank/emaste/src/freebsd-xlld/tmp/usr/lib/crtbeginT.o -L/tank/emaste/obj/tank/emaste/src/freebsd-xlld/tmp/usr/lib -L/tank/emaste/obj/tank/emaste/src/freebsd-xlld/tmp/lib -L/tank/emaste/obj/tank/emaste/src/freebsd-xlld/tmp/usr/lib app.o as.o atof-generic.o atof-ieee.o cond.o depend.o dw2gencfi.o dwarf2dbg.o ecoff.o ehopt.o expr.o flonum-copy.o flonum-konst.o flonum-mult.o frags.o hash.o input-file.o input-scrub.o listing.o literal.o macro.o messages.o obj-elf.o output-file.o read.o sb.o stabs.o subsegs.o symbols.o write.o tc-i386.o ../libbfd/libbfd.a ../libiberty/libiberty.a ../libopcodes/libopcodes.a -lgcc -lgcc_eh -lc -lgcc -lgcc_eh /tank/emaste/obj/tank/emaste/src/freebsd-xlld/tmp/usr/lib/crtend.o /tank/emaste/obj/tank/emaste/src/freebsd-xlld/tmp/usr/lib/crtn.o

Current executable set to '/tank/emaste/src/freebsd-xlld/tools_bin/ld' (x86_64).
(lldb) run
Process 99104 launching
Process 99104 stopped
(lldb) Process 99104 launched: '/tank/emaste/src/freebsd-xlld/tools_bin/ld' (x86_64)
Assertion failed: (isa<X>(Val) && "cast<Ty>() argument of incompatible type!"), function cast, file ../include/llvm/Support/Casting.h, line 237.
Process 99104 stopped
* (lldb) thread #1: tid = 105448, 0x0000000803aa2aaa libc.so.7`__sys_thr_kill + 10 at thr_kill.S:3, stop reason = signal SIGABRT
    frame #0: 0x0000000803aa2aaa libc.so.7`__sys_thr_kill + 10 at thr_kill.S:3
   1    #include "compat.h"
   2    #include "SYS.h"
-> 3    RSYSCALL(thr_kill)
   4            .section .note.GNU-stack,"",%progbits
(lldb) bt
* thread #1: tid = 105448, 0x0000000803aa2aaa libc.so.7`__sys_thr_kill + 10 at thr_kill.S:3, stop reason = signal SIGABRT
  * frame #0: 0x0000000803aa2aaa libc.so.7`__sys_thr_kill + 10 at thr_kill.S:3
    frame #1: 0x0000000803aa2a96 libc.so.7`__raise(s=<unavailable>) + 38 at raise.c:51
    frame #2: 0x0000000803aa2a19 libc.so.7`abort + 73 at abort.c:65
    frame #3: 0x0000000803b093c1 libc.so.7`__assert(func=<unavailable>, file=<unavailable>, line=<unavailable>, failedexpr=<unavailable>) + 81 at assert.c:54
    frame #4: 0x0000000001858757 ld`llvm::object::ELFFile<llvm::object::ELFType<(llvm::support::endianness)1, true> >::uintX_t lld::elf2::getLocalRelTarget<llvm::object::ELFType<(llvm::support::endianness)1, true>, true>(lld::elf2::ObjectFile<llvm::object::ELFType<(llvm::support::endianness)1, true> > const&, llvm::object::Elf_Rel_Impl<llvm::object::ELFType<(llvm::support::endianness)1, true>, true> const&) + 535
    frame #5: 0x000000000184e7ea ld`void lld::elf2::InputSectionBase<llvm::object::ELFType<(llvm::support::endianness)1, true> >::relocate<true>(unsigned char*, unsigned char*, llvm::iterator_range<llvm::object::Elf_Rel_Impl<llvm::object::ELFType<(llvm::support::endianness)1, true>, true> const*>) + 362
    frame #6: 0x000000000184e5c1 ld`lld::elf2::InputSection<llvm::object::ELFType<(llvm::support::endianness)1, true> >::writeTo(unsigned char*) + 241
    frame #7: 0x000000000185e39b ld`lld::elf2::OutputSection<llvm::object::ELFType<(llvm::support::endianness)1, true> >::writeTo(unsigned char*) + 43
    frame #8: 0x00000000018828c6 ld`(anonymous namespace)::Writer<llvm::object::ELFType<(llvm::support::endianness)1, true> >::run() + 11398
    frame #9: 0x000000000188ff79 ld`void lld::elf2::writeResult<llvm::object::ELFType<(llvm::support::endianness)1, true> >(lld::elf2::SymbolTable<llvm::object::ELFType<(llvm::support::endianness)1, true> >*) + 1049
    frame #10: 0x000000000183e4da ld`void lld::elf2::LinkerDriver::link<llvm::object::ELFType<(llvm::support::endianness)1, true> >(llvm::opt::InputArgList&) + 522
    frame #11: 0x000000000183c431 ld`lld::elf2::LinkerDriver::main(llvm::ArrayRef<char const*>) + 177
    frame #12: 0x000000000183c32c ld`lld::elf2::link(llvm::ArrayRef<char const*>) + 396
    frame #13: 0x000000000043a407 ld`lld::UniversalDriver::link(llvm::MutableArrayRef<char const*>, llvm::raw_ostream&) + 1591
    frame #14: 0x0000000000439da6 ld`main + 86
    frame #15: 0x0000000000439c6f ld`_start(ap=<unavailable>, cleanup=<unavailable>) + 367 at crt1.c:78

with debug:

(lldb) Process 3889 launched: '/tank/emaste/src/llvm/build-debug/bin/lld' (x86_64)
Assertion failed: (isa<X>(Val) && "cast<Ty>() argument of incompatible type!"), function cast, file ../include/llvm/Support/Casting.h, line 237.
Process 3889 stopped
(lldb) * thread #1: tid = 105373, 0x0000000805762aaa libc.so.7`__sys_thr_kill + 10 at thr_kill.S:3, stop reason = signal SIGABRT
    frame #0: 0x0000000805762aaa libc.so.7`__sys_thr_kill + 10 at thr_kill.S:3
   1    #include "compat.h"
   2    #include "SYS.h"
-> 3    RSYSCALL(thr_kill)
   4            .section .note.GNU-stack,"",%progbits
(lldb) bt
* thread #1: tid = 105373, 0x0000000805762aaa libc.so.7`__sys_thr_kill + 10 at thr_kill.S:3, stop reason = signal SIGABRT
  * frame #0: 0x0000000805762aaa libc.so.7`__sys_thr_kill + 10 at thr_kill.S:3
    frame #1: 0x0000000805762a96 libc.so.7`__raise(s=<unavailable>) + 38 at raise.c:51
    frame #2: 0x0000000805762a19 libc.so.7`abort + 73 at abort.c:65
    frame #3: 0x00000008057c93c1 libc.so.7`__assert(func=<unavailable>, file=<unavailable>, line=<unavailable>, failedexpr=<unavailable>) + 81 at assert.c:54
    frame #4: 0x0000000002928a29 lld`llvm::cast_retty<lld::elf2::MergeInputSection<llvm::object::ELFType<(Val=0x00000008064bd2a0)1, true> >, lld::elf2::InputSectionBase<llvm::object::ELFType<(llvm::support::endianness)1, true> >*>::ret_type llvm::cast<lld::elf2::MergeInputSection<llvm::object::ELFType<(llvm::support::endianness)1, true> >, lld::elf2::InputSectionBase<llvm::object::ELFType<(llvm::support::endianness)1, true> > >(lld::elf2::InputSectionBase<llvm::object::ELFType<(llvm::support::endianness)1, true> >*) + 73 at Casting.h:237
    frame #5: 0x0000000002954e30 lld`llvm::object::ELFFile<llvm::object::ELFType<(File=0x00000008064533c0, RI=0x0000000806488020)1, true> >::uintX_t lld::elf2::getLocalRelTarget<llvm::object::ELFType<(llvm::support::endianness)1, true>, true>(lld::elf2::ObjectFile<llvm::object::ELFType<(llvm::support::endianness)1, true> > const&, llvm::object::Elf_Rel_Impl<llvm::object::ELFType<(llvm::support::endianness)1, true>, true> const&) + 544 at OutputSections.h:819
    frame #6: 0x000000000292cb9e lld`void lld::elf2::InputSectionBase<llvm::object::ELFType<(this=0x00000008064bd000, Buf=0x000000080705b000, BufEnd=0x000000080705b27b, Rels=iterator_range<const llvm::object::Elf_Rel_Impl<llvm::object::ELFType<1, true>, true> *> at 0x00007fffffffbef8)1, true> >::relocate<true>(unsigned char*, unsigned char*, llvm::iterator_range<llvm::object::Elf_Rel_Impl<llvm::object::ELFType<(llvm::support::endianness)1, true>, true> const*>) + 766 at InputSection.cpp:123
    frame #7: 0x000000000292c819 lld`lld::elf2::InputSection<llvm::object::ELFType<(this=0x00000008064bd000, Buf=0x000000080705b000)1, true> >::writeTo(unsigned char*) + 425 at InputSection.cpp:168
    frame #8: 0x00000000029671c7 lld`lld::elf2::OutputSection<llvm::object::ELFType<(this=0x0000000806c15000, Buf=0x000000080705b000)1, true> >::writeTo(unsigned char*) + 359 at OutputSections.cpp:863
    frame #9: 0x0000000002a08571 lld`(anonymous namespace)::Writer<llvm::object::ELFType<(this=0x00007fffffffc430)1, true> >::writeSections() + 673 at Writer.cpp:990
    frame #10: 0x00000000029ef7f8 lld`(anonymous namespace)::Writer<llvm::object::ELFType<(this=0x00007fffffffc430)1, true> >::run() + 136 at Writer.cpp:147
    frame #11: 0x0000000002a36109 lld`void lld::elf2::writeResult<llvm::object::ELFType<(Symtab=0x00007fffffffd340)1, true> >(lld::elf2::SymbolTable<llvm::object::ELFType<(llvm::support::endianness)1, true> >*) + 1401 at Writer.cpp:135
    frame #12: 0x00000000028f57ae lld`void lld::elf2::LinkerDriver::link<llvm::object::ELFType<(this=0x00007fffffffd990, Args=0x00007fffffffd7f0)1, true> >(llvm::opt::InputArgList&) + 2366 at Driver.cpp:287
    frame #13: 0x00000000028edbf6 lld`lld::elf2::LinkerDriver::main(this=0x00007fffffffd990, ArgsArr=ArrayRef<const char *> at 0x00007fffffffd948) + 358 at Driver.cpp:126
    frame #14: 0x00000000028eda60 lld`lld::elf2::link(Args=ArrayRef<const char *> at 0x00007fffffffdba0) + 144 at Driver.cpp:37
    frame #15: 0x000000000044c580 lld`lld::UniversalDriver::link(args=MutableArrayRef<const char *> at 0x00007fffffffded8, diagnostics=0x000000000460e4b8) + 944 at UniversalDriver.cpp:208
    frame #16: 0x000000000044c081 lld`main(argc=54, argv=0x00007fffffffdfc0) + 97 at lld.cpp:35
    frame #17: 0x000000000044bf3f lld`_start(ap=<unavailable>, cleanup=<unavailable>) + 367 at crt1.c:78
(lldb) frame select 4
frame #4: 0x0000000002928a29 lld`llvm::cast_retty<lld::elf2::MergeInputSection<llvm::object::ELFType<(Val=0x00000008064bd2a0)1, true> >, lld::elf2::InputSectionBase<llvm::object::ELFType<(llvm::support::endianness)1, true> >*>::ret_type llvm::cast<lld::elf2::MergeInputSection<llvm::object::ELFType<(llvm::support::endianness)1, true> >, lld::elf2::InputSectionBase<llvm::object::ELFType<(llvm::support::endianness)1, true> > >(lld::elf2::InputSectionBase<llvm::object::ELFType<(llvm::support::endianness)1, true> >*) + 73 at Casting.h:237
   234 
   235  template <class X, class Y>
   236  inline typename cast_retty<X, Y *>::ret_type cast(Y *Val) {
-> 237    assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!");
   238    return cast_convert_val<X, Y*,
   239                            typename simplify_type<Y*>::SimpleType>::doit(Val);
   240  }
(lldb) up
frame #5: 0x0000000002954e30 lld`llvm::object::ELFFile<llvm::object::ELFType<(File=0x00000008064533c0, RI=0x0000000806488020)1, true> >::uintX_t lld::elf2::getLocalRelTarget<llvm::object::ELFType<(llvm::support::endianness)1, true>, true>(lld::elf2::ObjectFile<llvm::object::ELFType<(llvm::support::endianness)1, true> > const&, llvm::object::Elf_Rel_Impl<llvm::object::ELFType<(llvm::support::endianness)1, true>, true> const&) + 544 at OutputSections.h:819
(lldb) up
frame #6: 0x000000000292cb9e lld`void lld::elf2::InputSectionBase<llvm::object::ELFType<(this=0x00000008064bd000, Buf=0x000000080705b000, BufEnd=0x000000080705b27b, Rels=iterator_range<const llvm::object::Elf_Rel_Impl<llvm::object::ELFType<1, true>, true> *> at 0x00007fffffffbef8)1, true> >::relocate<true>(unsigned char*, unsigned char*, llvm::iterator_range<llvm::object::Elf_Rel_Impl<llvm::object::ELFType<(llvm::support::endianness)1, true>, true> const*>) + 766 at InputSection.cpp:123
   120      // resolved so we don't allocate a SymbolBody.
   121      const Elf_Shdr *SymTab = File->getSymbolTable();
   122      if (SymIndex < SymTab->sh_info) {
-> 123        uintX_t SymVA = getLocalRelTarget(*File, RI);
   124        Target->relocateOne(BufLoc, BufEnd, Type, AddrLoc, SymVA);
   125        continue;
   126      }
(lldb)