# Nightly can't compile aster-0.4.10 (windows 64bit)

#1

I’m trying to use serde, and for that I need to work with nightly, since the compiler plugin of serde is not yet supported in stable.
Yesterday I updated the compiler and now I’m totally stuck because the dependencies don’t compile anymore. I get an error in crate aster:

C:\msys64\home\emabee.cargo\registry\src\github.com-0a35038f75765ae4\aster-0.4.10\src\item.rs:462:18: 462:32 error: use of undeclared type name ast::StructDef [E0412]
C:\msys64\home\emabee.cargo\registry\src\github.com-0a35038f75765ae4\aster-0.4.10\src\item.rs:462 impl Invoke<Past::StructDef> for ItemStructBuilder
emabee ^~~~~~~~~~~~~~
C:\msys64\home\emabee.cargo\registry\src\github.com-0a35038f75765ae4\aster-0.4.10\src\item.rs:462:18: 462:32 help: run rustc --explain E0412 to see a detailed explanation
C:\msys64\home\emabee.cargo\registry\src\github.com-0a35038f75765ae4\aster-0.4.10\src\item.rs:467:35: 467:49 error: use of undeclared type name ast::StructDef [E0412]
C:\msys64\home\emabee.cargo\registry\src\github.com-0a35038f75765ae4\aster-0.4.10\src\item.rs:467 fn invoke(self, struct_def: Past::StructDef) -> F::Result {
emabee ^~~~~~~~~~~~~~
C:\msys64\home\emabee.cargo\registry\src\github.com-0a35038f75765ae4\aster-0.4.10\src\item.rs:467:35: 467:49 help: run rustc --explain E0412 to see a detailed explanation

Going back one version of aster did not help (error messages are slightly different though).

So it seems to be an issue of rustc nightly.

#2

I already fixed it for nightly in https://github.com/serde-rs/aster/pull/43

But I think syntex also needs to be adjusted (so stable/beta doesn’t break). The usual time needed from nightly doing a breaking change until serde works again is around a week. Be patient or stay with an older compiler until serde updates.

#3

At least on windows, the nigthly installer overwrites what I have. If the new nightly makes a problem, I need to re-install the old version. Is there a way to download older versions of nightly if I did not keep a local copy of the old installer?

#4

indeed there is. Every single rustc back to \$bigbang (almost, I forget where the before 2014 compilers are): https://static.rust-lang.org/dist/