Rust 1.100 will end host toolchains for 32-bit Windows; cross-compiling stays supported
The Rust project plans to demote the i686 Windows targets to std-only, so compilers will no longer be distributed for 32-bit Windows hosts.
The Rust blog has announced that, starting with Rust 1.100.0, the i686-pc-windows-msvc target moves from Tier 1 with host tools to Tier 1 without host tools, and i686-pc-windows-gnu moves from Tier 2 with host tools to Tier 2 without host tools.
Prebuilt standard library builds will still be distributed, and the MSVC target will continue to be tested in CI. What goes away is the compiler and other host tools for these targets, so toolchains can no longer be installed on 32-bit Windows machines after 1.100.
The project's stated reasons are that 32-bit-only desktop and server x86 CPUs have not been sold for over 15 years, general 32-bit Windows support ended in October 2025, and building these toolchains has caused compiler crashes and out-of-memory failures. Developers who still ship 32-bit Windows binaries should build them by cross-compiling from a supported host such as 64-bit Windows. Other 32-bit platforms are not affected.
Sources
Verified Oct 22, 2026 (official source). rustdeveloper-toolswindowscompiler