https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99000
Nathan Sidwell <nathan at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |SUSPENDED Last reconfirmed| |2021-02-08 Ever confirmed|0 |1 --- Comment #1 from Nathan Sidwell <nathan at gcc dot gnu.org> --- You're hitting this: @emph{G++'s modules support is not complete.} Other than bugs, the known missing pieces are: .... @item Textual merging of reachable GM entities Entities may be multiply defined across different header-units. These must be de-duplicated, and this is implemented across imports, or when an import redefines a textually-defined entity. However the reverse is not implemented---textually redefining an entity that has been defined in an imported header-unit. A redefinition error is emitted.