Do you have "Build with MSBuild instead of xbuild(EXPERIMENTAL)" setting enabled?
@Akin can you look into this? Who has to fix this? F# .targets or MSBuild?
Basically `_DebugFileExt` is not set to .mdb and F# compiler produces .mdb which is not copied to output folder...
Opened a PR with the fix: https://github.com/xamarin/xamarin-macios/pull/1642
I have checked this issue with both master and C9 builds and observed that now this issue isa not exists.
Breakpoint gets hit successfully with F# iOS application.
Screencast with C9 builds: https://www.screencast.com/t/yRMsiwbQng
Screencast with master builds: https://www.screencast.com/t/pMhtxxEtgi
Hence closing this issue.