Gleam 1.19 skips Erlang parsing and improves crash locations

Gleam 1.19 changes how it builds programs for the Erlang virtual machine. Instead of generating Erlang source text, it emits the compiler’s intermediate syntax representation directly, skipping tokenization and parsing. The change also preserves original Gleam source locations, making crash reports more useful. Erlang’s compiler still handles the later optimization and bytecode generation stages.

Gleam · Oct 5, 2026

Why it matters

This is a practical compiler improvement for engineers building typed applications on the BEAM runtime.

More context

Try the released compiler on an existing project and compare clean builds and stack traces. The release also explains why directly generating BEAM bytecode would increase maintenance costs as the virtual machine evolves. This is an update to Gleam, not a new language launch.

Keep in mind

The published speed comparison uses a deliberately repetitive synthetic project. It does not establish a universal build-speed ranking. Better metadata could support debuggers, but the team has not implemented that debugger work.

Original read