Assert in SRE during Boo compiler run with Mono 6.6

[tpokorra]

We have a build issue with boo on Fedora Rawhide, with Mono 6.6
It sounds very much like https://xamarin.github.io/bugzilla-archives/45/45136/bug.html, but that was already fixed in Mono 5.0.

see https://bugzilla.redhat.com/show_bug.cgi?id=1799197

Boo.NAnt.Tasks:

     [exec] /root/rpmbuild/BUILD/boo-alpha/default.build(308,4): Attribute 'useruntimeengine' for <exec ... /> is deprecated.  Use the managed attribute and Managed property instead.
     [exec] Boo Compiler version 0.9.7.0 (6.6.0.161 (tarball Wed Feb  5 07:34:41 UTC 2020))
     [exec] * Assertion at sre-encode.c:290, condition `count > 0' not met
     [exec] 
     [exec] 
     [exec] =================================================================
     [exec]  Native Crash Reporting
     [exec] =================================================================
     [exec] Got a SIGABRT while executing native code. This usually indicates
     [exec] a fatal error in the mono runtime or one of the native libraries 
     [exec] used by your application.
     [exec] =================================================================
     [exec] 
     [exec] =================================================================
     [exec]  Native stacktrace:
     [exec] =================================================================
     [exec]  0x55e28ab90425 - /usr/bin/mono : (null)
     [exec]  0x55e28ab907d0 - /usr/bin/mono : (null)
     [exec]  0x55e28ab3c952 - /usr/bin/mono : (null)
     [exec]  0x55e28ab8f9d7 - /usr/bin/mono : (null)
     [exec]  0x7ff1d69b9a90 - /lib64/libpthread.so.0 : (null)
     [exec]  0x7ff1d67fca35 - /lib64/libc.so.6 : gsignal
     [exec]  0x7ff1d67e5895 - /lib64/libc.so.6 : abort
     [exec]  0x55e28aaf83b0 - /usr/bin/mono : (null)
     [exec]  0x55e28ae05095 - /usr/bin/mono : (null)
     [exec]  0x55e28ae22447 - /usr/bin/mono : monoeg_assertion_message
     [exec]  0x55e28ad80491 - /usr/bin/mono : (null)
     [exec]  0x55e28ad80540 - /usr/bin/mono : (null)
     [exec]  0x55e28ad80bb5 - /usr/bin/mono : (null)
     [exec]  0x55e28ad82f14 - /usr/bin/mono : (null)
     [exec]  0x55e28ad85d51 - /usr/bin/mono : (null)
     [exec]  0x55e28ad7f97b - /usr/bin/mono : (null)
     [exec]  0x404256ed - Unknown
     [exec] 
     [exec] =================================================================
     [exec]  Telemetry Dumper:
     [exec] =================================================================
     [exec] Pkilling 0x7ff1d66d7700 from 0x7ff1d67bb780
     [exec] Entering thread summarizer pause from 0x7ff1d67bb780
     [exec] Finished thread summarizer pause from 0x7ff1d67bb780.
     [exec] * Assertion: should not be reached at threads.c:6254
     [exec] 
     [exec] Waiting for dumping threads to resume
     [exec] 
     [exec] =================================================================
     [exec]  External Debugger Dump:
     [exec] =================================================================
     [exec] mono_gdb_render_native_backtraces not supported on this platform, unable to find gdb or lldb
     [exec] 
     [exec] =================================================================
     [exec]  Basic Fault Address Reporting
     [exec] =================================================================
     [exec] Memory around native instruction pointer (0x7ff1d67fca35):0x7ff1d67fca25  d2 4c 89 ce bf 02 00 00 00 b8 0e 00 00 00 0f 05  .L..............
     [exec] 0x7ff1d67fca35  48 8b 84 24 08 01 00 00 64 48 2b 04 25 28 00 00  H..$....dH+.%(..
     [exec] 0x7ff1d67fca45  00 75 24 44 89 c0 48 81 c4 18 01 00 00 c3 0f 1f  .u$D..H.........
     [exec] 0x7ff1d67fca55  44 00 00 48 8b 15 19 64 18 00 f7 d8 41 b8 ff ff  D..H...d....A...
     [exec] 
     [exec] =================================================================
     [exec]  Managed Stacktrace:
     [exec] =================================================================
     [exec]    at <unknown> <0xffffffff>
     [exec]    at System.Reflection.Emit.ModuleBuilder:build_metadata <0x0006c>
     [exec]    at System.Reflection.Emit.ModuleBuilder:Save <0x0072b>
     [exec]    at System.Reflection.Emit.AssemblyBuilder:Save <0x007eb>
     [exec]    at System.Reflection.Emit.AssemblyBuilder:Save <0x0003b>
     [exec]    at Boo.Lang.Compiler.Steps.SaveAssembly:Save <0x0011b>
     [exec]    at Boo.Lang.Compiler.Steps.SaveAssembly:Run <0x0007f>
     [exec]    at Boo.Lang.Compiler.CompilerPipeline:RunStep <0x000e4>
     [exec]    at Boo.Lang.Compiler.CompilerPipeline:RunSteps <0x0009f>
     [exec]    at <Run>c__AnonStorey0:<>m__0 <0x00073>
     [exec]    at Boo.Lang.Environments.ActiveEnvironment:With <0x00072>
     [exec]    at Boo.Lang.Compiler.CompilerPipeline:Run <0x0014f>
     [exec]    at Boo.Lang.Compiler.BooCompiler:Run <0x000a9>
     [exec]    at Boo.Lang.Compiler.BooCompiler:Run <0x00053>
     [exec]    at booc.App:Run <0x0026f>
     [exec]    at booc.App:AppRun <0x0003f>
     [exec]    at booc.App:Main <0x00063>
     [exec]    at <Module>:runtime_invoke_int_object <0x00091>
     [exec] =================================================================

BUILD FAILED - 0 non-fatal error(s), 31 warning(s)

[stakx]

We've encountered the same problem in castleproject/Core#485.

Complete error message in build log: https://ci.appveyor.com/project/castleproject/core/builds/31404023/job/61opul2pxlnxlybk#L111

#mono --version
Mono JIT compiler version 6.8.0.105 (tarball Tue Feb  4 21:20:20 UTC 2020)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
	TLS:           __thread
	SIGSEGV:       altstack
	Notifications: epoll
	Architecture:  amd64
	Disabled:      none
	Misc:          softdebug 
	Interpreter:   yes
	LLVM:          yes(610)
	Suspend:       hybrid
	GC:            sgen (concurrent by default)

[raxod502]

Same issue when trying to run NCC to compile Nemerle code through Mono on Ubuntu:

# cat main.n                                                                                                                                                                                     
System.Console.WriteLine("Hello, world!");                                                                                                                                                                         
# mono /opt/nemerle/ncc.exe main.n -out:main.exe                                                                                                                                                 
* Assertion at sre-encode.c:290, condition `count > 0' not met                                           

[... lots of output omitted ...]