I am trying to fix dub compilation of D-Scanner for the fork that uses libdmd [1]. Executing just dub build yields this error:

collect2: error: ld returned 1 exit status
Error: undefined reference to `ModuleInfo for dmd.iasm`
Error: undefined reference to `dmd.iasm.asmSemantic(dmd.dsymbol.CAsmDeclaration, dmd.dscope.Scope*)`
       referenced from `_ZN22DsymbolSemanticVisitor5visitEP15CAsmDeclaration`
Error: undefined reference to `ModuleInfo for dmd.iasm`
Error: undefined reference to `dmd.iasm.asmSemantic(dmd.statement.AsmStatement, dmd.dscope.Scope*)`
       referenced from `void dmd.statementsem.statementSemanticVisit(dmd.statement.Statement, dmd.dscope.Scope*).visitAsm(dmd.statement.AsmStatement)`
Error: undefined reference to `initializer for dmd.astenums.Edition`
       perhaps a library needs to be added with the `-L` flag or `pragma(lib, ...)`
Error: linker exited with status 1

Adding the missing files in dub.sdl solved the issue:

- excludedSourceFiles "compiler/src/dmd/iasm/*"
+ excludedSourceFiles "compiler/src/dmd/iasm/dmd*"

Now there is a new error showing up:

collect2: error: ld returned 1 exit status
Error: undefined reference to `structalign_t::setPack()`
       referenced from `void dmd.cparse.CParser!(dmd.astcodegen.ASTCodegen).CParser.cparseDeclspec(ref dmd.cparse.CParser!(dmd.astcodegen.ASTCodegen).CParser.Specifier)`
Error: undefined reference to `structalign_t::setPack()`
       referenced from `void dmd.cparse.CParser!(dmd.astcodegen.ASTCodegen).CParser.cparseGnuAttribute(ref dmd.cparse.CParser!(dmd.astcodegen.ASTCodegen).CParser.Specifier)`
Error: undefined reference to `structalign_t::setAlignas()`
       referenced from `dmd.dsymbol.Dsymbol dmd.cparse.CParser!(dmd.astcodegen.ASTCodegen).CParser.applySpecifier(dmd.dsymbol.Dsymbol, ref dmd.cparse.CParser!(dmd.astcodegen.ASTCodegen).CParser.Specifier)`
Error: undefined reference to `structalign_t::setPack()`
       referenced from `nothrow void dmd.cparse.CParser!(dmd.astcodegen.ASTCodegen).CParser.pragmaPack(dmd.location.Loc, bool).setPackAlign(ref const(dmd.tokens.Token))`
Error: undefined reference to `initializer for dmd.astenums.Edition`
       perhaps a library needs to be added with the `-L` flag or `pragma(lib, ...)`
Error: linker exited with status 1

This made me think the file that defines structalign_t (astenums.d) is somehow ignored, but from the dub.sdl file it looks like it's not the case.

Do you have any idea how to sort this out? Perhaps there is something more to consider to make the fork compilable via dub?