據查，今年很早就不能用brew install --with-training-tools tesseract 安裝可訓練的tesseract了，
https://blog.csdn.net/weixin_39569611/article/details/87278729
於是根據https://github.com/tesseract-ocr/tesseract/wiki/Compiling#macos
中的步驟：
git clone https://github.com/tesseract-ocr/tesseract/
cd tesseract
./autogen.sh
./configure CC=gcc-8 CXX=g++-8 CPPFLAGS=-I/usr/local/opt/icu4c/include LDFLAGS=-L/usr/local/opt/icu4c/lib
make -j
sudo make install # if desired make training # if installed with training dependencies
但編譯時，在./configure**** 這一步出錯，錯誤爲：
........
checking for icu-i18n >= 52.1... no
configure: WARNING: icu 52.1 or higher is required, but was not found.
configure: WARNING: Training tools WILL NOT be built.
configure: WARNING: Try to install libicu-devel package.
checking for pango >= 1.22.0... no
configure: WARNING: pango 1.22.0 or higher is required, but was not found.
configure: WARNING: Training tools WILL NOT be built.
configure: WARNING: Try to install libpango1.0-dev package.
checking for cairo... no
configure: WARNING: Training tools WILL NOT be built because of missing cairo library.
configure: WARNING: Try to install libcairo-dev?? package.
checking that generated files are newer than configure... done
configure: creating ./config.status
config.status: creating Makefile
config.status: creating tesseract.pc
..............
config.status: executing libtool commands
Configuration is done.
You can now build and install tesseract by running:
$ make
$ sudo make install
$ sudo ldconfig
Documentation will not be built because asciidoc or xsltproc is missing.
You can not build training tools because of missing dependency. (警告中出現的那些找不到的dependency)
Check configure output for details.
主要是幾個警告，導致最後出現You can not build training tools because of missing dependency.
brew install cairo pango icu4c autoconf libffi libarchive
export PKG_CONFIG_PATH=\
$(brew --prefix)/lib/pkgconfig:\
$(brew --prefix)/opt/libarchive/lib/pkgconfig:\
$(brew --prefix)/opt/icu4c/lib/pkgconfig:\
$(brew --prefix)/opt/libffi/lib/pkgconfig
./configure
成功。