fix(build): restore precompiled MLN builds by ciscorn · Pull Request #242 · maplibre/maplibre-native-rs

ciscorn · 2026-06-17T23:08:21Z

I found MLN_PRECOMPILE=1 builds are currently broken, but this was not caught by CI. This PR updates the precompiled MapLibre Native release and fixes the link setup:

(Some of these changes are based on #237 by @yuiseki - thanks!)

Update the precompiled MLN release to the latest core release
Restore the vendored bridge include path
Link required system libraries for precompiled builds (libuv on non-Apple targets, sqlite3 on Apple targets)
Avoid direct mapbox::geojson symbols from the Rust bridge, since they are hidden in the amalgam
Comment out now-unused GeoJson::to_json_string() - no public mbgl API yet feat(core): Add public stringifyGeoJSON to mbgl::style::conversion maplibre-native#4345
Add precompiled CI coverage to prevent regressions

Note: macOS still does not work with MLN_PRECOMPILE=1 because the amalgam (built with armerge --keep-symbols 'mbgl.*') also hides the C++ exception RTTI symbols.

Copilot

Pull request overview

This PR restores support for MLN_PRECOMPILE=1 builds by updating the precompiled MapLibre Native release metadata, fixing build-script include/link configuration, and adding CI coverage to prevent future regressions.

Changes:

Bump the precompiled MapLibre Native release tag used by MLN_PRECOMPILE=1.
Restore the vendored bridge include/ directory to the C++ bridge include path.
Link libuv only on non-Apple targets in the build script, and exercise precompiled builds in CI.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
Cargo.toml	Updates `package.metadata.mln.release` to a newer precompiled MapLibre Native core tag.
build.rs	Restores bridge include dirs (adds `include/`) and adjusts `libuv` linking to be non-Apple only.
.github/workflows/ci.yml	Switches selected matrix legs to `precompiled: 1` / `amalgam: 1` to cover precompiled builds in CI.

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Copilot

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 11 comments.

Co-authored-by: yuiseki <yui.matsumura@geolonia.com>

yuiseki · 2026-06-18T03:32:37Z

Thank you for referring to my PR!

FYI:
I've sent a small PR to publish mbgl::style::conversion::stringifyGeoJSON to maplibre-native:

feat(core): Add public stringifyGeoJSON to mbgl::style::conversion maplibre-native#4345

I think it may be helpful for maplibre-native-rs.

ciscorn · 2026-06-18T05:14:27Z

@yuiseki Thanks. I switched the stringify parts I'd removed to commented-out instead🙏

Murmele · 2026-06-18T06:24:19Z

    return std::make_unique<GeoJson>(geojson.get());
 }

-rust::String stringify(const GeoJson& geojson) {


Shall we add a feature flag and disable conditionally?

I think keeping it commented out and waiting for maplibre/maplibre-native#4345 is the safe option here, rather than adding a feature flag.

Reasons:

A flag can't link against anything until stringifyGeoJSON ships; then we just un-comment it — no flag needed.

Gating one method — with no clear use case yet — needs a lot of plumbing.

We're actively embracing breaking changes for now.

Murmele · 2026-06-18T06:27:33Z

-    tick_until_ready(|| request.is_ready());

-    let image = request.finish().expect("geometry-fit renderer should render");
+    let image = request.wait().expect("geometry-fit renderer should render");


Can we name it wait_finish? Because wait is quite generic?

I agree that wait may be a bit generic. That said, this is the blocking utility for a render request, so I think RenderRequest::wait() is still acceptable, similar to JoinHandle::join() or process::Child::wait().

Of course, suggestions to improve the name are very welcome.

Murmele · 2026-06-18T06:30:10Z

+
+    // The precompiled headers tarball omits `platform/default/` headers
+    // (e.g. `mbgl/gfx/headless_frontend.hpp`), so add vendored fallbacks.
+    let root = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());


We should do this only for amalgam. We don't need this include folder when compiling our self

I think this is already scoped that way! It's only added inside bundle_precompiled(), so source builds don't pull it in.

CommanderStorm · 2026-06-18T10:13:47Z

          - runs-on: ubuntu-latest
            backend: vulkan
-            precompiled: 0
-            amalgam: 0
+            precompiled: 1
+            amalgam: 1


Please add another variant to the matrix not remove a variant from ci.
If CI thakes longer because of this, this is preferable to not checking a path that we could have checked imo

I was hesitant to grow the matrix, but I think it's the right call. Added it. Thanks!

Yes, growing beyond 10 jobs means that one gets queued, unless github has extra capa, but that is fine.

CommanderStorm

I am fine with this change, but I would prefer if we wait the maybe week or so that the PR in native would take. Seems like an easy fix.

Thanks @yuiseki for looking into this ❤️

ciscorn · 2026-06-18T11:20:13Z

Thanks for the review and approval 🙏❤️

A small scope note, since the GeoJSON discussion may have drawn the focus: the core fix here is the broken MLN_PRECOMPILE=1 build (include path, libuv/sqlite3, CI coverage). The only caveat is that it temporarily comments out to_json_string() — which I'd added alongside parse() without a real use case, and which is blocking this MLN_PRECOMPILE=1 fix.

CommanderStorm · 2026-06-18T13:23:54Z

if there is no real usecase behind this, I am fine with removing it (incl the commnted out code) as well.
Your (and @yuiseki's) call.

ciscorn · 2026-06-19T05:31:44Z

Thanks! Merging this now. I'll re-enable the commented-out lines once @yuiseki's maplibre/maplibre-native#4345 lands.

feat(core): Add public stringifyGeoJSON to mbgl::style::conversion maplibre-native#4345

fix(build): restore precompiled MLN builds

43cf05e

ciscorn requested review from CommanderStorm, Murmele and Copilot June 17, 2026 23:08

Copilot started reviewing on behalf of ciscorn June 17, 2026 23:08 View session

Copilot AI reviewed Jun 17, 2026

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link sqlite3 when building on Apple

672ed55

ciscorn marked this pull request as draft June 17, 2026 23:14

ciscorn removed request for CommanderStorm and Murmele June 17, 2026 23:14

ciscorn force-pushed the fix-precompiled branch from 36b307e to 812e606 Compare June 18, 2026 00:05

ciscorn requested review from CommanderStorm, Murmele and Copilot June 18, 2026 01:31

ciscorn marked this pull request as ready for review June 18, 2026 01:32

Copilot started reviewing on behalf of ciscorn June 18, 2026 01:32 View session

Copilot AI reviewed Jun 18, 2026

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ciscorn force-pushed the fix-precompiled branch from 4915b1a to cf5edac Compare June 18, 2026 01:59

ciscorn and others added 2 commits June 18, 2026 11:53

avoid hidden GeoJSON symbols in precompiled builds

fd70575

Co-authored-by: yuiseki <yui.matsumura@geolonia.com>

fix macos tests

9c3f848

ciscorn force-pushed the fix-precompiled branch from cf5edac to 9c3f848 Compare June 18, 2026 02:54

comment out the geojson serializer API

a4d959a

Murmele reviewed Jun 18, 2026

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ciscorn requested a review from Murmele June 18, 2026 07:27

CommanderStorm reviewed Jun 18, 2026

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ci: add linux vulkan precompiled path

623132a

CommanderStorm approved these changes Jun 18, 2026

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CommanderStorm mentioned this pull request Jun 18, 2026

feat: update to mlt-core 0.11.1 maplibre/martin#2899

Merged

ciscorn merged commit b2bb93d into maplibre:main Jun 19, 2026
29 of 31 checks passed

ciscorn deleted the fix-precompiled branch June 19, 2026 05:34

CommanderStorm mentioned this pull request Jun 17, 2026

chore: release #236

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