with_sess called before set_parse_sess on nightly

[anna-is-cute]

cargo build output

   Compiling html5ever v0.22.2
   Compiling dotenv v0.11.0
   Compiling git2 v0.7.1
   Compiling string_cache v0.7.2
   Compiling markup5ever v0.7.2
   Compiling tokio-proto v0.1.1
   Compiling tokio-tls v0.1.4
   Compiling ring v0.13.0-alpha
error: failed to run custom build command for `string_cache v0.7.2`
process didn't exit successfully: `/Users/kyleclemens/Code/Rust/Projects/paste/target/debug/build/string_cache-d56e68a236f49db5/build-script-build` (exit code: 101)
--- stderr
thread 'main' panicked at 'proc_macro::__internal::with_sess() called before set_parse_sess()!', libproc_macro/lib.rs:1319:9
stack backtrace:
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
   1: std::sys_common::backtrace::print
   2: std::panicking::default_hook::{{closure}}
   3: std::panicking::default_hook
   4: std::panicking::rust_panic_with_hook
   5: std::panicking::begin_panic
   6: proc_macro::__internal::with_sess
   7: proc_macro2::imp::Span::call_site
             at /Users/kyleclemens/.cargo/registry/src/github.com-1ecc6299db9ec823/proc-macro2-0.3.6/src/unstable.rs:223
   8: proc_macro2::Span::_new
             at /Users/kyleclemens/.cargo/registry/src/github.com-1ecc6299db9ec823/proc-macro2-0.3.6/src/lib.rs:186
   9: siphasher::sip::u8to64_le
             at /Users/kyleclemens/.cargo/registry/src/github.com-1ecc6299db9ec823/string_cache_codegen-0.4.1/lib.rs:217
  10: siphasher::sip::u8to64_le
             at /Users/kyleclemens/.cargo/registry/src/github.com-1ecc6299db9ec823/string_cache_codegen-0.4.1/lib.rs:172
  11: string_cache_codegen::AtomType::to_tokens::{{closure}}
             at /Users/kyleclemens/.cargo/registry/src/github.com-1ecc6299db9ec823/string_cache_codegen-0.4.1/lib.rs:272
  12: build_script_build::main
             at ./build.rs:7
  13: std::rt::lang_start::{{closure}}
             at /Users/travis/build/rust-lang/rust/src/libstd/rt.rs:74
  14: std::panicking::try::do_call
  15: __rust_maybe_catch_panic
  16: std::rt::lang_start_internal
  17: std::rt::lang_start
             at /Users/travis/build/rust-lang/rust/src/libstd/rt.rs:74
  18: build_script_build::main

warning: build failed, waiting for other jobs to finish...
error: failed to run custom build command for `html5ever v0.22.2`
process didn't exit successfully: `/Users/kyleclemens/Code/Rust/Projects/paste/target/debug/build/html5ever-a52d56e779889e57/build-script-build` (exit code: 101)
--- stderr
thread 'main' panicked at 'proc_macro::__internal::with_sess() called before set_parse_sess()!', libproc_macro/lib.rs:1319:9
stack backtrace:
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
   1: std::sys_common::backtrace::print
   2: std::panicking::default_hook::{{closure}}
   3: std::panicking::default_hook
   4: std::panicking::rust_panic_with_hook
   5: std::panicking::begin_panic
   6: proc_macro::__internal::with_sess
   7: <proc_macro::TokenStream as core::str::FromStr>::from_str
   8: core::alloc::Layout::align
             at /Users/travis/build/rust-lang/rust/src/libcore/str/mod.rs:2550
   9: core::clone::impls::<impl core::clone::Clone for bool>::clone
             at /Users/travis/build/rust-lang/rust/src/liballoc/str.rs:1814
  10: proc_macro2::imp::LexError
             at /Users/kyleclemens/.cargo/registry/src/github.com-1ecc6299db9ec823/proc-macro2-0.3.6/src/unstable.rs:30
  11: core::alloc::Layout::align
             at /Users/travis/build/rust-lang/rust/src/libcore/str/mod.rs:2550
  12: core::clone::impls::<impl core::clone::Clone for bool>::clone
             at /Users/travis/build/rust-lang/rust/src/liballoc/str.rs:1814
  13: <syntax::parse::token::DelimToken as core::clone::Clone>::clone
             at /Users/kyleclemens/.cargo/registry/src/github.com-1ecc6299db9ec823/proc-macro2-0.3.6/src/lib.rs:85
  14: <proc_macro2::TokenStream as core::clone::Clone>::clone
             at /Users/travis/build/rust-lang/rust/src/libcore/str/mod.rs:2550
  15: <alloc::alloc::Global as core::alloc::Alloc>::realloc
             at /Users/travis/build/rust-lang/rust/src/liballoc/str.rs:1814
  16: syn::parse2::{{closure}}
             at /Users/kyleclemens/.cargo/registry/src/github.com-1ecc6299db9ec823/syn-0.13.1/src/lib.rs:640
  17: syn::parse2::{{closure}}
             at /Users/kyleclemens/.cargo/registry/src/github.com-1ecc6299db9ec823/syn-0.13.1/src/lib.rs:705
  18: build_script_build::match_token::expand
             at ./macros/match_token.rs:114
  19: build_script_build::main
             at ./build.rs:24
  20: std::rt::lang_start::{{closure}}
             at /Users/travis/build/rust-lang/rust/src/libstd/rt.rs:74
  21: std::panicking::try::do_call
  22: __rust_maybe_catch_panic
  23: std::rt::lang_start_internal
  24: std::rt::lang_start
             at /Users/travis/build/rust-lang/rust/src/libstd/rt.rs:74
  25: build_script_build::main

warning: build failed, waiting for other jobs to finish...
error[E0425]: cannot find value `f` in this scope
 --> /Users/kyleclemens/.cargo/registry/src/github.com-1ecc6299db9ec823/dotenv-0.11.0/src/errors.rs:3:17
  |
3 | #[derive(Debug, ErrorChain)]
  |                 ^^^^^^^^^^ not found in this scope

error: aborting due to previous error

For more information about this error, try `rustc --explain E0425`.
error: Could not compile `dotenv`.
warning: build failed, waiting for other jobs to finish...
error: failed to run custom build command for `markup5ever v0.7.2`
process didn't exit successfully: `/Users/kyleclemens/Code/Rust/Projects/paste/target/debug/build/markup5ever-3a7d0e3731af9f38/build-script-build` (exit code: 101)
--- stderr
thread 'main' panicked at 'proc_macro::__internal::with_sess() called before set_parse_sess()!', libproc_macro/lib.rs:1319:9
stack backtrace:
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
   1: std::sys_common::backtrace::print
   2: std::panicking::default_hook::{{closure}}
   3: std::panicking::default_hook
   4: std::panicking::rust_panic_with_hook
   5: std::panicking::begin_panic
   6: proc_macro::__internal::with_sess
   7: proc_macro2::imp::Span::call_site
             at /Users/kyleclemens/.cargo/registry/src/github.com-1ecc6299db9ec823/proc-macro2-0.3.6/src/unstable.rs:223
   8: proc_macro2::Span::_new
             at /Users/kyleclemens/.cargo/registry/src/github.com-1ecc6299db9ec823/proc-macro2-0.3.6/src/lib.rs:186
   9: siphasher::sip::u8to64_le
             at /Users/kyleclemens/.cargo/registry/src/github.com-1ecc6299db9ec823/string_cache_codegen-0.4.1/lib.rs:217
  10: string_cache_codegen::AtomType::write_to
             at /Users/kyleclemens/.cargo/registry/src/github.com-1ecc6299db9ec823/string_cache_codegen-0.4.1/lib.rs:172
  11: build_script_build::main
             at ./build.rs:51
  12: std::rt::lang_start::{{closure}}
             at /Users/travis/build/rust-lang/rust/src/libstd/rt.rs:74
  13: std::panicking::try::do_call
  14: __rust_maybe_catch_panic
  15: std::rt::lang_start_internal
  16: std::rt::lang_start
             at /Users/travis/build/rust-lang/rust/src/libstd/rt.rs:74
  17: <build_script_build::named_entities_to_phf::_IMPL_DESERIALIZE_FOR_CharRef::<impl serde::de::Deserialize<'de> for build_script_build::named_entities_to_phf::CharRef>::deserialize::__Visitor<'de> as serde::de::Visitor<'de>>::visit_map

warning: build failed, waiting for other jobs to finish...
error: build failed

---

This looks awfully similar to #41610.

This is on rustc 1.27.0-nightly (ac3c2288f 2018-04-18), but I can reproduce back to 2018-04-16. I can't test further back because a library restricts the compiler version to newer than 04-16.

macOS 10.13.4, Rust installed via rustup and not brew.

Reproduced on ubuntu Docker image and on a Debian 9 Linode.

This example repository will produce this issue when cargo build is used.

[BigBigos]

Hi,

I can also reproduce this problem on Linux with rustup. It happens when I try to compile string_cache that has a build.rs script that uses string_cache_codegen which subsequently relies on proc_macro2.

The oldest nightly version that reproduces this issue is nightly-2018-04-06 (rust version 1.27.0-nightly (48fa6f963 2018-04-05)). Older versions cannot compile proc_macro2 (due to this commit) which is needed for string_cache_codegen (see above).

After debugging more, it seems that something (?) enables the nightly feature of proc_macro2 which is broken. Running a simple test case (just run quote!() from the quote crate) reproduces this issue when nightly feature is enabled in proc_macro2 but does not reproduce by default. I will create another bug report for the broken nightly feature.

[BigBigos]

@jkcclemens

Your problem seems to be caused by the existence of codegen_next crate in the Rocket repo. It enables the nigthly feature of proc-macro2 which is then shared and used this way in string_cache_codegen which is unsupported.

I guess you cannot build anything using quote!() outside of procedural macros (like string_cache) when this nightly feature is enabled by at least a single dependency.

[anna-is-cute]

Are there any plans to fix this? It's been a month of no progress, so just curious if it has been looked at.

[Centril]

@jkcclemens If you could provide a minimal reproducer that would help towards fixing this.

[jyn514]

Your problem seems to be caused by the existence of codegen_next crate in the Rocket repo. It enables the nigthly feature of proc-macro2 which is then shared and used this way in string_cache_codegen which is unsupported.

This sounds like a bug in proc-macro2, not the compiler itself. I haven't seen other issues related to string_cache_codegen so I suspect this was fixed in a later version of proc-macro2.