mac$ git clone https://github.com/weissi/swift-nio
mac$ git checkout jw-asyncawait
mac$ docker run -it --rm --privileged -w "$PWD" -v "$PWD:$PWD" swiftlang/swift:nightly-main-bionic

docker$ swift build -Xswiftc -Xfrontend -Xswiftc -enable-experimental-concurrency
docker$ lldb .build/x86_64-unknown-linux-gnu/debug/NIOAsyncAwaitDemo

(lldb) break set -f main.swift -l 38
(lldb) break set -f main.swift -l 45
(lldb) break set -f main.swift -l 47
(lldb) break set -f main.swift -l 52
(lldb) break set -f main.swift -l 55

(lldb) run
(lldb) bt

(lldb) run
Process 221 launched: '/Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/NIOAsyncAwaitDemo' (x86_64)
Process 221 stopped
* thread #​3, name = 'NIOAsyncAwaitDe', stop reason = breakpoint 1.1
    frame #​0: 0x0000555555713225 NIOAsyncAwaitDemo`main() at main.swift:38:15
   35   func main() async {
   36       do {
   37           let channel = try await makeHTTPChannel(host: "httpbin.org", port: 80)
-> 38           print("OK, connected to \(channel)")
   39   
   40           print("Sending request 1", terminator: "")
   41           let response1 = try await channel.sendRequest(HTTPRequestHead(version: .http1_1,
Target 1: (NIOAsyncAwaitDemo) stopped.
(lldb) bt
warning: (x86_64) /Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/NIOAsyncAwaitDemo 0x00007c61: Module /Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/ModuleCache/21W7O8BKIMLPP/CNIOLinux-2B1XW2SH7FMQ7.pcm is out-of-date (hash mismatch). Type information from this module may be incomplete or inconsistent with the rest of the program. Rebuilding the project will regenerate the needed module files.
warning: (x86_64) /Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/NIOAsyncAwaitDemo 0x00007c8b: Module /Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/ModuleCache/21W7O8BKIMLPP/Dispatch-1MKLX15782NIB.pcm is out-of-date (hash mismatch). Type information from this module may be incomplete or inconsistent with the rest of the program. Rebuilding the project will regenerate the needed module files.
warning: (x86_64) /Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/NIOAsyncAwaitDemo 0x00009dc6: Module /Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/ModuleCache/21W7O8BKIMLPP/SwiftGlibc-1DO298432GENU.pcm is out-of-date (hash mismatch). Type information from this module may be incomplete or inconsistent with the rest of the program. Rebuilding the project will regenerate the needed module files.
warning: (x86_64) /Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/NIOAsyncAwaitDemo 0x0000b40e: Module /Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/ModuleCache/21W7O8BKIMLPP/SwiftGlibc-1DO298432GENU.pcm is out-of-date (hash mismatch). Type information from this module may be incomplete or inconsistent with the rest of the program. Rebuilding the project will regenerate the needed module files.
warning: (x86_64) /Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/NIOAsyncAwaitDemo 0x0007460f: Module /Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/ModuleCache/21W7O8BKIMLPP/CNIOAtomics-2C3ET3BDNTJTE.pcm is out-of-date (hash mismatch). Type information from this module may be incomplete or inconsistent with the rest of the program. Rebuilding the project will regenerate the needed module files.
warning: (x86_64) /Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/NIOAsyncAwaitDemo 0x0007a909: Module /Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/ModuleCache/21W7O8BKIMLPP/SwiftOverlayShims-1KFO504FT44T.pcm is out-of-date (hash mismatch). Type information from this module may be incomplete or inconsistent with the rest of the program. Rebuilding the project will regenerate the needed module files.
warning: (x86_64) /Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/NIOAsyncAwaitDemo 0x0007b0e1: Module /Users/johannes/devel/swift-nio/.build/x86_64-unknown-linux-gnu/debug/ModuleCache/21W7O8BKIMLPP/CNIOHTTPParser-1MXR9LJ3A513M.pcm is out-of-date (hash mismatch). Type information from this module may be incomplete or inconsistent with the rest of the program. Rebuilding the project will regenerate the needed module files.
lldb: /home/buildnode/jenkins/workspace/oss-swift-package-linux-ubuntu-18_04/llvm-project/llvm/include/llvm/Support/Casting.h:104: static bool llvm::isa_impl_cl<lldb_private::SwiftASTContext, const lldb_private::TypeSystem *>::doit(const From *) [To = lldb_private::SwiftASTContext, From = const lldb_private::TypeSystem *]: Assertion `Val && "isa<> used on a null pointer"' failed.
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace.
Stack dump:
0.  Program arguments: lldb .build/x86_64-unknown-linux-gnu/debug/NIOAsyncAwaitDemo
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
lldb[0x431303]
lldb[0x42f3ee]
lldb[0x43192c]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x12980)[0x7f7531184980]
/lib/x86_64-linux-gnu/libc.so.6(gsignal+0xc7)[0x7f7525cdffb7]
/lib/x86_64-linux-gnu/libc.so.6(abort+0x141)[0x7f7525ce1921]
/lib/x86_64-linux-gnu/libc.so.6(+0x3048a)[0x7f7525cd148a]
/lib/x86_64-linux-gnu/libc.so.6(+0x30502)[0x7f7525cd1502]
/usr/bin/../lib/liblldb.so.10git(+0x14e3783)[0x7f7528707783]
/usr/bin/../lib/liblldb.so.10git(+0x14ec6f0)[0x7f75287106f0]
/usr/bin/../lib/liblldb.so.10git(+0x102350b)[0x7f752824750b]
/usr/bin/../lib/liblldb.so.10git(+0xf65725)[0x7f7528189725]
/usr/bin/../lib/liblldb.so.10git(+0xf64dbe)[0x7f7528188dbe]
/usr/bin/../lib/liblldb.so.10git(+0xf8672f)[0x7f75281aa72f]
/usr/bin/../lib/liblldb.so.10git(+0x12eb443)[0x7f752850f443]
/usr/bin/../lib/liblldb.so.10git(+0xf271e5)[0x7f752814b1e5]
/usr/bin/../lib/liblldb.so.10git(+0xf26a03)[0x7f752814aa03]
/usr/bin/../lib/liblldb.so.10git(+0xf26a03)[0x7f752814aa03]
/usr/bin/../lib/liblldb.so.10git(+0xf265cc)[0x7f752814a5cc]
/usr/bin/../lib/liblldb.so.10git(+0x10b0361)[0x7f75282d4361]
/usr/bin/../lib/liblldb.so.10git(+0x10b0a55)[0x7f75282d4a55]
/usr/bin/../lib/liblldb.so.10git(+0x10b5b18)[0x7f75282d9b18]
/usr/bin/../lib/liblldb.so.10git(+0x10f0770)[0x7f7528314770]
/usr/bin/../lib/liblldb.so.10git(+0x16a0c33)[0x7f75288c4c33]
/usr/bin/../lib/liblldb.so.10git(+0x16a90ee)[0x7f75288cd0ee]
/usr/bin/../lib/liblldb.so.10git(+0xff4368)[0x7f7528218368]
/usr/bin/../lib/liblldb.so.10git(+0xfea1b9)[0x7f752820e1b9]
/usr/bin/../lib/liblldb.so.10git(+0x1671d66)[0x7f7528895d66]
/usr/bin/../lib/liblldb.so.10git(+0xff461e)[0x7f752821861e]
/usr/bin/../lib/liblldb.so.10git(+0xfea1b9)[0x7f752820e1b9]
/usr/bin/../lib/liblldb.so.10git(+0xfedf0a)[0x7f7528211f0a]
/usr/bin/../lib/liblldb.so.10git(+0xf2f281)[0x7f7528153281]
/usr/bin/../lib/liblldb.so.10git(+0xf11296)[0x7f7528135296]
/usr/bin/../lib/liblldb.so.10git(+0xfef77d)[0x7f752821377d]
/usr/bin/../lib/liblldb.so.10git(_ZN4lldb10SBDebugger21RunCommandInterpreterEbb+0xf7)[0x7f7527de4017]
lldb[0x40a9ac]
lldb[0x40ce9a]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xe7)[0x7f7525cc2bf7]
lldb[0x40702a]
********************
Crash reproducer for lldb version 10.0.0 (git@github.com:apple/llvm-project.git revision 5f17b63a89d10af44cbe3ae43a77dee9003ceb42)
Swift version 5.4-dev (LLVM 5f17b63a89d10af, Swift bdacb68b83b67b8)

Reproducer written to '/tmp/reproducer-3f1184'

Before attaching the reproducer to a bug report:
 - Look at the directory to ensure you're willing to share its content.
 - Make sure the reproducer works by replaying the reproducer.

Replay the reproducer with the following command:
lldb -replay /tmp/reproducer-3f1184
********************
Aborted