---
name: dev-setup
type: reference
tags: [setup, dependencies, build, linux, fedora]
description: Authoritative build dependencies and launch instructions for Kon on Fedora Linux
---

# Kon — Developer Setup

Last updated: 2026/04/18. Primary dev target: Fedora 43, x86_64, KDE Wayland, NVIDIA RTX 4070.

---

## System dependencies

### Required (CPU build)

```bash
sudo dnf install cmake clang-devel
```

| Package | Why |
|---|---|
| `cmake` | whisper-rs-sys build system |
| `clang-devel` | bindgen header generation for whisper-rs-sys |

**Fedora-specific:** `libclang.so` lives in `/usr/lib64/llvm21/lib64/`, not on the standard search path. Set permanently:

```bash
set -Ux LIBCLANG_PATH /usr/lib64/llvm21/lib64
```

Or prefix every build command:

```bash
LIBCLANG_PATH=/usr/lib64/llvm21/lib64 npm run tauri dev
```

### Required (Vulkan GPU build)

```bash
sudo dnf install vulkan-headers vulkan-loader-devel glslc
```

| Package | Why |
|---|---|
| `vulkan-headers` | `vulkan.h` needed by ggml-vulkan CMake |
| `vulkan-loader-devel` | `libvulkan.so` link target for CMake |
| `glslc` | Compiles GLSL compute shaders to SPIR-V at build time |

The NVIDIA Vulkan ICD (`nvidia_icd.json`) is included in the standard NVIDIA driver package — no extra install needed if the driver is already installed.

---

## Node / Rust

```bash
npm install          # frontend deps — run once after clone
```

Rust toolchain managed by `rustup`. No extra steps needed beyond what Tauri requires.

---

## Launch commands

### CPU build (default)

```bash
cd /home/jake/Documents/CORBEL-Projects/kon
LIBCLANG_PATH=/usr/lib64/llvm21/lib64 npm run tauri dev
```

Once `set -Ux LIBCLANG_PATH` is in fish config, this becomes:

```bash
npm run tauri dev
```

### Vulkan GPU build

Same command — the `whisper-vulkan` feature flag is already set in `crates/transcription/Cargo.toml`. First build compiles Vulkan compute shaders and takes longer than usual.

Confirm GPU is active in startup logs:

```
whisper_backend_init_gpu: device 0: NVIDIA GeForce RTX 4070   ← GPU active
```

vs CPU fallback:

```
whisper_backend_init_gpu: device 0: CPU (type: 0)             ← no GPU
```

---

## Startup log reference

Normal startup sequence:

```
[startup] Wayland workaround: GDK_BACKEND=x11
[startup] DB init: ~4ms
[startup] Preferences load: ~200µs
[startup] Whisper model pre-warmed successfully
```

The Wayland workarounds are injected automatically by `ensure_x11_on_wayland()` in `src-tauri/src/lib.rs` — no manual env-var prefix needed.

---

## Known build gotchas

| Issue | Cause | Fix |
|---|---|---|
| `Unable to find libclang` | Fedora puts clang libs in versioned path | `set -Ux LIBCLANG_PATH /usr/lib64/llvm21/lib64` |
| `Could NOT find Vulkan (missing: glslc)` | Shader compiler not installed | `sudo dnf install vulkan-headers vulkan-loader-devel glslc` |
| `there is no reactor running` | `tokio::spawn` called before runtime starts in `setup()` | Use `tauri::async_runtime::spawn` instead |
| `effect_update_depth_exceeded` | Svelte 5 `$state` object reassigned instead of mutated | Use `Object.assign(state, updates)` — never spread-replace module-level state |

---

## GPU notes

- **Vulkan** is the GPU backend used here. CUDA is not required.
- `crates/transcription/Cargo.toml` feature: `whisper-vulkan` → `whisper-rs/vulkan` → `ggml-vulkan`
- CPU and GPU builds are otherwise identical — same binary, same model files.
- Expected speedup on RTX 4070: ~10–15× over CPU for `whisper-base.en`.
