{"record":{"id":"c7266050ca52f3f3","repo":"emilk/egui","slug":"failed-to-construct-c-string-from-string-for-gl-pr","errorCode":null,"errorMessage":"failed to construct C string from string for gl proc address","messagePattern":"failed to construct C string from string for gl proc address","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/eframe/src/native/glow_integration.rs","lineNumber":227,"sourceCode":"\n        let mut glutin_window_context = unsafe {\n            GlutinWindowContext::new(egui_ctx, winit_window_builder, native_options, event_loop)?\n        };\n\n        // Creates the window - must come before we create our glow context\n        glutin_window_context.initialize_window(ViewportId::ROOT, event_loop)?;\n\n        {\n            let viewport = &glutin_window_context.viewports[&ViewportId::ROOT];\n            let window = viewport.window.as_ref().unwrap(); // Can't fail - we just called `initialize_all_viewports`\n            epi_integration::apply_window_settings(window, window_settings);\n        }\n\n        let gl = unsafe {\n            profiling::scope!(\"glow::Context::from_loader_function\");\n            Arc::new(glow::Context::from_loader_function(|s| {\n                let s = std::ffi::CString::new(s)\n                    .expect(\"failed to construct C string from string for gl proc address\");\n\n                glutin_window_context.get_proc_address(&s)\n            }))\n        };\n\n        let painter = egui_glow::Painter::new(\n            gl,\n            \"\",\n            native_options.glow_options.shader_version,\n            native_options.dithering,\n        )?;\n\n        Ok((glutin_window_context, painter))\n    }\n\n    fn init_run_state(\n        &mut self,\n        event_loop: &ActiveEventLoop,","sourceCodeStart":209,"sourceCodeEnd":245,"githubUrl":"https://github.com/emilk/egui/blob/8fb03c9ae9a6bf1ffa602dfba51ed575f2655975/crates/eframe/src/native/glow_integration.rs#L209-L245","documentation":"Error \"failed to construct C string from string for gl proc address\" thrown in emilk/egui.","triggerScenarios":"Thrown at crates/eframe/src/native/glow_integration.rs:227 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["A GL function name contained an interior NUL byte: strip NUL characters before constructing the C string for the proc address lookup."],"exampleFix":"let cname = std::ffi::CString::new(name.replace('\\0', \"\")).expect(\"valid gl symbol name\");","handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"8fb03c9ae9a6bf1ffa602dfba51ed575f2655975","analyzedAt":"2026-08-19T12:39:57.743Z","contentChangedAt":"2026-08-19T12:39:57.743Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}