Why does Burst AOT fail with missing PDB on Windows?

Burst's AOT path on Windows uses MSVC link.exe to produce native binaries. Without Visual Studio Build Tools or Windows SDK installed, the link step can't find required libraries / generate PDB.

Visual Studio 2022 Community + Desktop development with C++ workload. Or standalone Build Tools for Visual Studio. Then Editor preferences → Burst → Use Platform SDK = true.

Linux/macOS equivalent?

On Linux, install build-essential. On macOS, Xcode Command Line Tools. Burst tries to invoke clang/lld; missing toolchain produces similar errors.

Fix: Unity Burst AOT Fails Missing PDB

Quick answer: Install Visual Studio Build Tools 2022 + C++ Desktop workload. Preferences → Burst → Use Platform SDK.

Build pipeline log: Failed to compile Burst job: missing PDB. Native toolchain absent on the build machine.

The Fix

Windows host:
  1. Install Build Tools for Visual Studio 2022
     (Tools → Get Tools and Features → Desktop development with C++)
  2. Re-launch Unity from the Developer Command Prompt
  3. Edit → Preferences → Burst:
       Use Platform SDK:    true
  4. Retry build.

CI:
  - Pre-bake build agent with VS Build Tools image
  - Or use unity-build-server image (includes toolchain)

Burst inspects the platform toolchain at build time. Missing pieces fail the link step that produces native PDBs.

Verifying

Build completes. Burst log shows compiled binaries with PDBs in Library/BurstCache/JIT.

“Toolchain present. PDB lands. Burst builds.”

Related Issues

For Burst FunctionPointer, see function pointer. For Burst determinism, see determinism.

VS Build Tools. Burst happy.