[core] Report conversion errors using std::string

char* increases the risk of pointing to a invalid reference. Qt had
to use a static variable as retainer to workaround.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/mbgl/style/sources/geojson_source_impl.cpp b/src/mbgl/style/sources/geojson_source_impl.cpp
index d71df28378..9e6b3d34f6 100644
--- a/src/mbgl/style/sources/geojson_source_impl.cpp
+++ b/src/mbgl/style/sources/geojson_source_impl.cpp
@@ -83,7 +83,7 @@ void GeoJSONSource::Impl::load(FileSource& fileSource) {
 
             conversion::Result<GeoJSON> geoJSON = conversion::convertGeoJSON<JSValue>(d);
             if (!geoJSON) {
-                Log::Error(Event::ParseStyle, "Failed to parse GeoJSON data: %s", geoJSON.error().message);
+                Log::Error(Event::ParseStyle, "Failed to parse GeoJSON data: %s", geoJSON.error().message.c_str());
                 // Create an empty GeoJSON VT object to make sure we're not infinitely waiting for
                 // tiles to load.
                 mapbox::geojson::feature_collection features;