Type: <b>Bug</b> I am developing a debugger for a language transpiled to C. I have studied GDB Python API and implemented pretty-printers for stack frames (`FrameFilter`/`FrameDecorator`) and custom data types (`ValuePrinter`) that work as expected both from VSCode debugger and from GDB CLI. For some reason, type pretty-printer (`TypePrinter`/`TypeRecognizer`) does not work when using VSCode debugger, but works as expected from GDB CLI. I have enabled pretty printing (`-enable-pretty-printing`) and frame filtering (`-enable-frame-filters`). I did not find any option for specifically enabling type pretty-printers in the VSCode documentation. I use `typedef` to denote custom types from my language so they can be observed as special types in GDB Python API. In GDB CLI, `ptype` should write type with unwrapped `typedef`-s, while `whatis` should write either type name (without unwrapping) or pretty-printed type (if type pretty-printer is installed). When I register custom type pretty-printer, both CLI commands behave as expected. VSCode debugger prints `typedef` name even if type-pretty printer is installed. This means that the behavior is equivalent to `whatis` without type-pretty printer. For this reason, I suspect that either VSCode does not properly interact with GCC DAP for type info or that GCC DAP implementation does not properly use type pretty-printers (which I consider as the less likely option). If needed, I can create a simplified version of custom debugger for reproduction purposes, stripped from unneeded details of my language. VS Code version: Code 1.93.1 (38c31bc77e0dd6ae88a4e9cc93428cc27a56ba40, 2024-09-11T17:20:05.685Z) OS version: Linux x64 6.8.0-49-generic Modes: <details> <summary>System Info</summary> |Item|Value| |---|---| |CPUs|Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz (8 x 3399)| |GPU Status|2d_canvas: enabled<br>canvas_oop_rasterization: enabled_on<br>direct_rendering_display_compositor: disabled_off_ok<br>gpu_compositing: enabled<br>multiple_raster_threads: enabled_on<br>opengl: enabled_on<br>rasterization: enabled<br>raw_draw: disabled_off_ok<br>skia_graphite: disabled_off<br>video_decode: enabled<br>video_encode: disabled_software<br>vulkan: disabled_off<br>webgl: enabled<br>webgl2: enabled<br>webgpu: disabled_off<br>webnn: disabled_off| |Load (avg)|1, 1, 1| |Memory (System)|15.36GB (8.63GB free)| |Process Argv|--crash-reporter-id d8473509-49e3-47f0-aa6d-823411298eb1| |Screen Reader|no| |VM|0%| |DESKTOP_SESSION|ubuntu| |XDG_CURRENT_DESKTOP|Unity| |XDG_SESSION_DESKTOP|ubuntu| |XDG_SESSION_TYPE|wayland| </details><details><summary>Extensions (11)</summary> Extension|Author (truncated)|Version ---|---|--- gcov-viewer|Jac|0.6.0 compare|Joz|0.0.3 debugpy|ms-|2024.12.0 python|ms-|2024.14.1 vscode-pylance|ms-|2024.11.3 cmake-tools|ms-|1.19.52 cpptools|ms-|1.22.11 cpptools-extension-pack|ms-|1.3.0 llvm|RRe|0.2.0 cmake|twx|0.0.17 vscode-typhoondsl|Typ|0.4.0 (1 theme extensions excluded) </details><details> <summary>A/B Experiments</summary> ``` vsliv368:30146709 vspor879:30202332 vspor708:30202333 vspor363:30204092 vscod805cf:30301675 binariesv615:30325510 vsaa593:30376534 py29gd2263:31024239 c4g48928:30535728 azure-dev_surveyone:30548225 962ge761:30959799 pythonnoceb:30805159 asynctok:30898717 pythonmypyd1:30879173 h48ei257:31000450 pythontbext0:30879054 cppperfnew:31000557 dsvsc020:30976470 pythonait:31006305 dsvsc021:30996838 f3je6385:31013174 dvdeprecation:31068756 dwnewjupytercf:31046870 nativerepl2:31139839 pythonrstrctxt:31112756 nativeloc1:31185841 cf971741:31144450 iacca1:31171482 notype1:31157159 5fd0e150:31155592 dwcopilot:31170013 stablechunks:31184530 ``` </details> <!-- generated by issue reporter -->