fresnel needs helix-term's MappableCommand roster and Keymaps dispatcher. Its build.rs otherwise fetches and compiles ~300 bundled tree-sitter grammars, one of which reproducibly fails to link on nix's toolchain under the concurrent build. Set HELIX_DISABLE_AUTO_GRAMMAR_BUILD=1 at the workspace level to skip that step — fresnel drives syntax highlighting through Pierre's Shiki path in Phase 2 and its own tree-sitter for syntax-aware collapse, so the bundled grammars aren't needed. Also set DEVELOPER_DIR so nix's gcc can find dsymutil for debug-info bundling on macOS.