compileAndBuildVLCKit.sh fails with Boost_INCLUDE_DIR-NOTFOUND

Running ./compileAndBuildVLCKit.sh -v -a all fails with the following output on macOS Catalina 10.15.7:

CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
Boost_INCLUDE_DIR
   used as include directory in directory /Users/jones/Documents/px4/VLCKit/libvlc/vlc/contrib/contrib-armv7-apple-iOS_9.0/taglib/taglib
   used as include directory in directory /Users/jones/Documents/px4/VLCKit/libvlc/vlc/contrib/contrib-armv7-apple-iOS_9.0/taglib/taglib
   used as include directory in directory /Users/jones/Documents/px4/VLCKit/libvlc/vlc/contrib/contrib-armv7-apple-iOS_9.0/taglib/taglib
   used as include directory in directory /Users/jones/Documents/px4/VLCKit/libvlc/vlc/contrib/contrib-armv7-apple-iOS_9.0/taglib/taglib
   used as include directory in directory /Users/jones/Documents/px4/VLCKit/libvlc/vlc/contrib/contrib-armv7-apple-iOS_9.0/taglib/taglib
   used as include directory in directory /Users/jones/Documents/px4/VLCKit/libvlc/vlc/contrib/contrib-armv7-apple-iOS_9.0/taglib/taglib

CMake Warning (dev) in taglib/CMakeLists.txt:
  Policy CMP0021 is not set: Fatal error on relative paths in
  INCLUDE_DIRECTORIES target property.  Run "cmake --help-policy CMP0021" for
  policy details.  Use the cmake_policy command to set the policy and
  suppress this warning.

  Found relative path while evaluating include directories of "tag":

    "Boost_INCLUDE_DIR-NOTFOUND"

This warning is for project developers.  Use -Wno-dev to suppress it.

CMake Warning (dev) in taglib/CMakeLists.txt:
  Policy CMP0021 is not set: Fatal error on relative paths in
  INCLUDE_DIRECTORIES target property.  Run "cmake --help-policy CMP0021" for
  policy details.  Use the cmake_policy command to set the policy and
  suppress this warning.

  Found relative path while evaluating include directories of "tag":

    "Boost_INCLUDE_DIR-NOTFOUND"

This warning is for project developers.  Use -Wno-dev to suppress it.

CMake Warning (dev) in taglib/CMakeLists.txt:
  Policy CMP0021 is not set: Fatal error on relative paths in
  INCLUDE_DIRECTORIES target property.  Run "cmake --help-policy CMP0021" for
  policy details.  Use the cmake_policy command to set the policy and
  suppress this warning.

  Found relative path while evaluating include directories of "tag":

    "Boost_INCLUDE_DIR-NOTFOUND"

This warning is for project developers.  Use -Wno-dev to suppress it.

-- Generating done
CMake Generate step failed.  Build files cannot be regenerated correctly.
make: *** [.taglib] Error 1
ERROR: Building contribs failed

I have boost installed from Homebrew. Any idea what could be wrong?