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OpenUSD usdcat とかが動かんときの対策メモ

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usd
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OpenUSD
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OpenUSD ビルドした!
(Python binding つき)

でも usdcat.exe しても動かん...(なんも print せん). usd と tbb の path 通しているのに...

原因

Python DLL のパスが通っていなかった.

解決

こーゆーときは Claude code くん使ってみましょう
私も Claude code で原因突き止めました.

結果としては usdcat.exe は tbb と usd の dll, そして usd dll は python binding つきでビルドしてあるので python.dll のパスも設定必要だった.

今回は Python は uv で入れたものだったので, AppData\Roaming\uv あたりに PATH を通して解決!
(PATH に設定しないと, たぶん Windows 標準の Python の dll を見に行ってダメなもよう)

以下 Claude クンのレポート.

Root Cause Analysis: usdcat.exe Silent Exit

Problem

usdcat.exe -h (or --version) silently exits with no output when environment is not configured.

Root Cause

Exit Code: -1073741515 (0xC0000135) = STATUS_DLL_NOT_FOUND

The Windows loader cannot find required DLLs, causing the process to terminate immediately before any code executes.

DLL Dependencies (Analysis via dumpbin)

Direct Dependencies of usdcat.exe:

usd_usdUtils.dll    → N:\work\dist-usd-reldeb\lib
usd_usd.dll         → N:\work\dist-usd-reldeb\lib
usd_sdf.dll         → N:\work\dist-usd-reldeb\lib
usd_tf.dll          → N:\work\dist-usd-reldeb\lib
usd_python.dll      → N:\work\dist-usd-reldeb\lib
python311.dll       → C:\Users\syoyo\AppData\Roaming\uv\python\cpython-3.11.13-windows-x86_64-none

Indirect Dependencies (via usd_tf.dll):

tbb12.dll           → N:\work\dist-tbb-reldeb\bin
python311.dll       → (same as above)

Required Environment Variables

MINIMUM Required (for usdcat to work):

set PATH=N:\work\dist-usd-reldeb\lib;N:\work\dist-tbb-reldeb\bin;C:\Users\syoyo\AppData\Roaming\uv\python\cpython-3.11.13-windows-x86_64-none;%PATH%

NOT Required (but useful for Python USD programming):

  • PYTHONPATH - Only needed when importing pxr modules from Python
  • PXR_PLUGINPATH_NAME - Only needed for custom USD plugins

Test Results Summary

PATH Components Result Exit Code
None FAIL -1073741515
USD lib only FAIL -1073741515
USD + TBB FAIL -1073741515
USD + Python FAIL -1073741515
TBB + Python FAIL -1073741515
USD + TBB + Python SUCCESS 0

DLL Dependency Chain

usdcat.exe
├── usd_usdUtils.dll ────┐
├── usd_usd.dll          │ All in N:\work\dist-usd-reldeb\lib
├── usd_sdf.dll          │ (requires this dir in PATH)
├── usd_tf.dll ──────────┘
│   ├── tbb12.dll ───────── In N:\work\dist-tbb-reldeb\bin (requires this in PATH)
│   └── python311.dll ──┐
└── python311.dll ───────┴── In C:\Users\syoyo\AppData\Roaming\uv\python\... (requires this in PATH)

Why Silent Exit?

When a Windows executable depends on a DLL that cannot be found:

  1. The Windows loader (kernel32.dll) attempts to load the EXE
  2. It resolves imports and tries to load required DLLs from PATH
  3. If ANY required DLL is missing, the process terminates with STATUS_DLL_NOT_FOUND
  4. No code in usdcat.exe ever executes - not even main()
  5. No error message is printed because the program never started

This is why:

  • usdcat --version shows nothing
  • usdcat -h shows nothing
  • The process just exits silently

Solution

Minimum working setup:

set PATH=N:\work\dist-usd-reldeb\lib;N:\work\dist-tbb-reldeb\bin;C:\Users\syoyo\AppData\Roaming\uv\python\cpython-3.11.13-windows-x86_64-none;%PATH%

Recommended setup (for full USD usage):

REM Required for all USD tools
set PATH=N:\work\dist-usd-reldeb\lib;N:\work\dist-tbb-reldeb\bin;C:\Users\syoyo\AppData\Roaming\uv\python\cpython-3.11.13-windows-x86_64-none;%PATH%

REM Required for Python USD imports
set PYTHONPATH=N:\work\dist-usd-reldeb\lib\python

REM Required for USD plugins (optional)
set PXR_PLUGINPATH_NAME=N:\work\dist-usd-reldeb\lib\usd

Quick Test

# Use the provided script
setup-usd-env.bat

# Or minimal test
set PATH=N:\work\dist-usd-reldeb\lib;N:\work\dist-tbb-reldeb\bin;C:\Users\syoyo\AppData\Roaming\uv\python\cpython-3.11.13-windows-x86_64-none;%PATH%
usdcat -h

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