What causes "precompiled erlang is not available: {reason}" in jdx/mise?

Enable source compilation: remove MISE_ERLANG_COMPILE=false or set erlang_compile = true in settings

precompiled erlang is not available

Error message

precompiled erlang is not available: {reason}

What it means

Erlang can be installed precompiled (Hex builds) or compiled from source. This bail fires when a precompiled build is unavailable for the requested platform/version AND the erlang_compile setting is explicitly Some(false), meaning mise is forbidden from falling back to source compilation.

Solutions

Enable source compilation: remove MISE_ERLANG_COMPILE=false or set erlang_compile = true in settings
Pick an Erlang version that has a precompiled build for your platform on builds.hex.pm
Change the platform/distro target (e.g. use a supported Ubuntu version) if you need precompiled
Pin a version known to have precompiled artifacts for musl-free Linux/macOS

Example fix

// before
MISE_ERLANG_COMPILE=false mise install erlang@26.0
// after
mise settings set erlang_compile true
mise install erlang@26.0

Defensive patterns

Strategy: fallback

Validate before calling

# check if compilation is allowed and platform has precompiled builds
mise settings get erlang_compile
uname -m  # confirm arch has hex.pm builds

Try / catch

catch (e) {
  if (/precompiled erlang is not available/.test(String(e))) {
    // enable erlang_compile or switch version/platform
  }
}

Prevention

Only set MISE_ERLANG_COMPILE=false if you've confirmed hex.pm has builds for your platform
Pin Erlang versions with known precompiled artifacts for your CI OS
Keep build toolchains installed even when preferring precompiled, as fallback

When it happens

Trigger: `mise install erlang@<version>` on a platform/version with no precompiled Hex build while `erlang_compile` is explicitly disabled in settings (e.g. MISE_ERLANG_COMPILE=false), so precompiled_unavailable becomes fatal instead of falling back.

Common situations: Users who disabled compilation for speed/CI hitting a platform gap (no Hex build for their distro/arch); CI configs that hard-set erlang_compile=false then request an unusual Erlang version.

Related errors

AI-assisted analysis of jdx/mise@533346cc37 (2026-09-17). Data as JSON: /api/errors/2fba0571c7b03363. Report an issue: GitHub.

Appendix: source

Thrown at src/plugins/core/erlang.rs:98

    }

    async fn install_kerl(&self) -> Result<()> {
        debug!("Installing kerl to {}", display_path(self.kerl_path()));
        HTTP_FETCH
            .download_file(
                format!("https://raw.githubusercontent.com/kerl/kerl/{KERL_VERSION}/kerl"),
                &self.kerl_path(),
                None,
            )
            .await?;
        file::make_executable(self.kerl_path())?;
        Ok(())
    }

    fn precompiled_unavailable(&self, reason: impl Into<String>) -> Result<Option<ToolVersion>> {
        let reason = reason.into();
        if Settings::get().erlang_compile(CompilePurpose::Inspect) == Some(false) {
            bail!("precompiled erlang is not available: {reason}");
        }
        debug!("{reason}");
        Ok(None)
    }

    fn release_tag(version: &str) -> String {
        format!("OTP-{version}")
    }

    fn lockfile_url(&self, locked: bool, tv: &ToolVersion) -> Option<String> {
        locked_platform_url(locked, &tv.lock_platforms, &self.get_platform_key())
    }

    fn set_lockfile_info(
        &self,
        tv: &mut ToolVersion,
        install: Option<&str>,
        url: &str,

View on GitHub (pinned to 533346cc37)