Trait implementation causes Object File Too Large error and compilation crash

[benwis]

For Leptos 0.7, we've switched our HTML rendering engine to use large recursive static types to represent the HTML tree, giving us significant benefits to final binary size and runtime speed, but unfortunately not to compile time.

To fix that, we've brought back the old behavior where we type erase the HTML components in the tree behind a feature flag for users to develop faster. However, we also added generic attribute spreading in this release to make our maintenance and user's code nicer and easier to write.

The crux of the issue here is implementing the trait that does that causes an error: cannot encode offset of relocations; object file too large on Mac after compiling for 10ish minutes and using 50GB of ram, with other issues on other platforms, but only with the AddAnyAttr trait. Not having attribute spreading in the type erased version severely limits its usefulness.

The trait can be found here but is basically this:

// Pre-erases output to reduce compile-time explosions
impl AddAnyAttr for AnyView {
    type Output<SomeNewAttr: Attribute> = AnyView;

    #[inline(never)]
    fn add_any_attr<NewAttr: Attribute>(
        self,
        attr: NewAttr,
    ) -> Self::Output<NewAttr>
    where
        Self::Output<NewAttr>: RenderHtml,
    {
        let attr = attr.into_cloneable_owned();
        let any_attr = attr.into_any_attr();
        self.value.dyn_add_any_attr(any_attr)
    }
}

A similar issue was discussed broadly here, but I wanted to provide a specific reproducer for a more targeted issue in the hopes of a solution or a workaround. Please let me know if this is out of line.

This can be reproduced by running cargo +stable build --bin demo --features ssr in the main branch of this repo.

To fix(and disable attribute spreading), in the workspace Cargo.toml change the leptos branch to "any-attr-disabled", see the extra commit on that branch for the minimal change that allows compilation to succeed in about 1m30s. This leads us to the idea that this specific trait implementation brakes everything, even though it seems to be perfectly valid Rust.

Thanks to @zakstucke and all the other Leptos users who have worked on this and tested various workarounds

[workingjubilee]

fascinating.

[benwis]

@workingjubilee This is not limited to Mac, it also crashes on Linux and probably Windows. Here is the stack trace for Linux on Fedora 16:

benwis in 🌐 seldon in thaw on  main via 🦀 v1.81.0 
❯ cargo +stable build --bin demo --features ssr
warning: profiles for the non root package will be ignored, specify profiles at the workspace root:
package:   /home/benwis/Downloads/thaw/demo/Cargo.toml
workspace: /home/benwis/Downloads/thaw/Cargo.toml
   Compiling demo v0.1.0 (/home/benwis/Downloads/thaw/demo)
error: rustc interrupted by SIGSEGV, printing backtrace

/home/benwis/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-3f4ebb066deec3c0.so(+0x32b0323) [0x71230b4b0323]
/usr/lib/libc.so.6(+0x3d1d0) [0x71230804c1d0]
/home/benwis/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/libLLVM.so.18.1-rust-1.81.0-stable(+0x62be442) [0x712306abe442]
/home/benwis/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/libLLVM.so.18.1-rust-1.81.0-stable(+0x62b2853) [0x712306ab2853]
/home/benwis/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/libLLVM.so.18.1-rust-1.81.0-stable(_ZN4llvm13FPPassManager13runOnFunctionERNS_8FunctionE+0x136f) [0x71230650f5af]
/home/benwis/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/libLLVM.so.18.1-rust-1.81.0-stable(_ZN4llvm13FPPassManager11runOnModuleERNS_6ModuleE+0x2f) [0x71230650e185]
/home/benwis/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/libLLVM.so.18.1-rust-1.81.0-stable(_ZN4llvm6legacy15PassManagerImpl3runERNS_6ModuleE+0x260) [0x712306ab0ea0]
/home/benwis/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-3f4ebb066deec3c0.so(LLVMRustWriteOutputFile+0x190) [0x71230d6624d0]
/home/benwis/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-3f4ebb066deec3c0.so(+0x54620df) [0x71230d6620df]
/home/benwis/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-3f4ebb066deec3c0.so(+0x545f5f0) [0x71230d65f5f0]
/home/benwis/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-3f4ebb066deec3c0.so(+0x545f25e) [0x71230d65f25e]
/home/benwis/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-3f4ebb066deec3c0.so(+0x545d6b4) [0x71230d65d6b4]
/home/benwis/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-3f4ebb066deec3c0.so(+0x545d1a9) [0x71230d65d1a9]
/home/benwis/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/libstd-1c4b19562077c20d.so(rust_metadata_std_1f2242ed6435445e+0xc75fb) [0x71230ed165fb]
/usr/lib/libc.so.6(+0x9439d) [0x7123080a339d]
/usr/lib/libc.so.6(+0x11949c) [0x71230812849c]

note: we would appreciate a report at https://github.com/rust-lang/rust
help: you can increase rustc's stack size by setting RUST_MIN_STACK=16777216
error: could not compile `demo` (lib)

Caused by:
  process didn't exit successfully: `/home/benwis/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/bin/rustc --crate-name demo --edition=2021 demo/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --diagnostic-width=150 --crate-type lib --emit=dep-info,metadata,link -C embed-bitcode=no -C debuginfo=2 --cfg 'feature="csr"' --cfg 'feature="default"' --cfg 'feature="ssr"' --check-cfg 'cfg(docsrs)' --check-cfg 'cfg(feature, values("csr", "default", "hydrate", "nightly", "ssr", "tracing"))' -C metadata=74f9f6f82da900f9 -C extra-filename=-74f9f6f82da900f9 --out-dir /home/benwis/Downloads/thaw/target/debug/deps -C incremental=/home/benwis/Downloads/thaw/target/debug/incremental -L dependency=/home/benwis/Downloads/thaw/target/debug/deps --extern cfg_if=/home/benwis/Downloads/thaw/target/debug/deps/libcfg_if-6afc45ef9c22aff9.rmeta --extern chrono=/home/benwis/Downloads/thaw/target/debug/deps/libchrono-a071519ce9432b48.rmeta --extern console_error_panic_hook=/home/benwis/Downloads/thaw/target/debug/deps/libconsole_error_panic_hook-def73760e3f683ed.rmeta --extern console_log=/home/benwis/Downloads/thaw/target/debug/deps/libconsole_log-e4bceb6fdbd9a06e.rmeta --extern demo_markdown=/home/benwis/Downloads/thaw/target/debug/deps/libdemo_markdown-585762e4e2e4faed.so --extern gloo_net=/home/benwis/Downloads/thaw/target/debug/deps/libgloo_net-c33a3db1dbd03c13.rmeta --extern icondata=/home/benwis/Downloads/thaw/target/debug/deps/libicondata-24a55c09ece64b6d.rmeta --extern js_sys=/home/benwis/Downloads/thaw/target/debug/deps/libjs_sys-a4a6c58932579698.rmeta --extern leptos=/home/benwis/Downloads/thaw/target/debug/deps/libleptos-03dc1254bb730a49.rmeta --extern leptos_meta=/home/benwis/Downloads/thaw/target/debug/deps/libleptos_meta-c8d114563dc0e233.rmeta --extern leptos_router=/home/benwis/Downloads/thaw/target/debug/deps/libleptos_router-5104eaa327e4c49e.rmeta --extern log=/home/benwis/Downloads/thaw/target/debug/deps/liblog-1141fc38e8923d7e.rmeta --extern palette=/home/benwis/Downloads/thaw/target/debug/deps/libpalette-fa9fe91759050312.rmeta --extern send_wrapper=/home/benwis/Downloads/thaw/target/debug/deps/libsend_wrapper-86494fb825b44e31.rmeta --extern thaw=/home/benwis/Downloads/thaw/target/debug/deps/libthaw-85a16e32ef484ed4.rmeta --extern uuid=/home/benwis/Downloads/thaw/target/debug/deps/libuuid-1d67e255752c3984.rmeta` (signal: 11, SIGSEGV: invalid memory reference)

[workingjubilee]

@benwis huh. what is the actual output on macOS?

[benwis]

@benwis huh. what is the actual output on macOS?

cargo +stable build --bin demo --features ssr
warning: profiles for the non root package will be ignored, specify profiles at the workspace root:
package:   /Users/zak/z/code/thaw/demo/Cargo.toml
workspace: /Users/zak/z/code/thaw/Cargo.toml
   Compiling thaw v0.4.1 (/Users/zak/z/code/thaw/thaw)
   Compiling demo v0.1.0 (/Users/zak/z/code/thaw/demo)
error: cannot encode offset of relocations; object file too large

error: could not compile `demo` (lib) due to 1 previous error

[luxalpa]

Just confirming that this is also an issue under Windows 11 / msvc:

stable-x86_64-pc-windows-msvc (default)
rustc 1.84.0 (9fc6b43 2025-01-07)

rustc-LLVM ERROR: out of memory
Allocation failed
error: could not compile `demo` (lib)

Caused by:
  process didn't exit successfully: `C:\Users\Luxalpa\.rustup\toolchains\stable-x86_64-pc-windows-msvc\bin\rustc.exe --crate-name demo --edition=2021 demo\src\lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --diagnostic-width=119 --crate-type lib --emit=dep-info,metadata,link -C embed-bitcode=no -C debuginfo=2 --cfg "feature=\"csr\"" --cfg "feature=\"default\"" --cfg "feature=\"ssr\"" --check-cfg cfg(docsrs) --check-cfg "cfg(feature, values(\"csr\", \"default\", \"hydrate\", \"nightly\", \"ssr\", \"tracing\"))" -C metadata=5e2bde8af5739bef -C extra-filename=-5e2bde8af5739bef --out-dir C:\projects_from_github\thaw\target\debug\deps -C incremental=C:\projects_from_github\thaw\target\debug\incremental -L dependency=C:\projects_from_github\thaw\target\debug\deps --extern cfg_if=C:\projects_from_github\thaw\target\debug\deps\libcfg_if-64bb2cffd428e39a.rmeta --extern chrono=C:\projects_from_github\thaw\target\debug\deps\libchrono-4997604bfdea4c35.rmeta --extern console_error_panic_hook=C:\projects_from_github\thaw\target\debug\deps\libconsole_error_panic_hook-e0851fc201ef9f25.rmeta --extern console_log=C:\projects_from_github\thaw\target\debug\deps\libconsole_log-cb9dfba97e19e4c9.rmeta --extern demo_markdown=C:\projects_from_github\thaw\target\debug\deps\demo_markdown-845ecd812a754256.dll --extern gloo_net=C:\projects_from_github\thaw\target\debug\deps\libgloo_net-99fd98a4ffb8597a.rmeta --extern icondata=C:\projects_from_github\thaw\target\debug\deps\libicondata-6e5c728b6b7b6956.rmeta --extern js_sys=C:\projects_from_github\thaw\target\debug\deps\libjs_sys-2b9929c1cb3fee66.rmeta --extern leptos=C:\projects_from_github\thaw\target\debug\deps\libleptos-1b52bd18fff8d698.rmeta --extern leptos_meta=C:\projects_from_github\thaw\target\debug\deps\libleptos_meta-07ae17ef97db0b63.rmeta --extern leptos_router=C:\projects_from_github\thaw\target\debug\deps\libleptos_router-341af47491526d64.rmeta --extern log=C:\projects_from_github\thaw\target\debug\deps\liblog-f90f0a800d58277c.rmeta --extern palette=C:\projects_from_github\thaw\target\debug\deps\libpalette-37de36958c75ce26.rmeta --extern send_wrapper=C:\projects_from_github\thaw\target\debug\deps\libsend_wrapper-0b6434e45d809341.rmeta --extern thaw=C:\projects_from_github\thaw\target\debug\deps\libthaw-ec8fa3c0c0c5e056.rmeta --extern uuid=C:\projects_from_github\thaw\target\debug\deps\libuuid-91c0ae681be859a7.rmeta -L native=C:\Users\Luxalpa\.cargo\registry\src\index.crates.io-6f17d22bba15001f\windows_x86_64_msvc-0.52.6\lib` (exit code: 0xc0000409, STATUS_STACK_BUFFER_OVERRUN)

libthaw-ec8fa3c0c0c5e056.rlib being 1.5 GB in size:

Also, it looks like my system is running out of memory: