Incorrect location of third-party source folder with --build option

[pablode]

Description of Issue

When USD is built using an explicit build directory:

python3 build_scripts/build_usd.py \
  --build BUILD \
  --openimageio \
  INSTALL

the 'src' folder for third-party libs resides in INSTALL/src and not in BUILD/src.

Since the downloaded sources are only relevant for the build process, I would expect them to reside in BUILD.

Steps to Reproduce

1. Build USD with above arguments
2. Observe location of 'src' folder

System Information (OS, Hardware)

MacBook Air M3, Sonoma 14.4.1

Package Versions

v24.05

Build Flags

See above.

[jesschimein]

Filed as internal issue #USD-9846

[pablode]

Ah, I just stumbled across --src SRC Directory where dependencies will be downloaded (default: <install_dir>/src). Sorry for the noise.