Imagick

In a perfect world, the only commands needed to compile Imagick are:

phpize
./configure
make install

• phpize - uses the scripts supplied by PHP to generate a make file
• ./configure - checks where all the headers are
• make install - makes and install

If you do run into problems, there are some options available through the configure program:

./configure --help

Probably the most useful one is being able to point where the ImageMagick headers + libraries live:

./configure --with-imagick=/opt/danack

./configure \
  --with-php-config=/opt/danack/bin/php-config \
  --with-imagick=/opt/danack

CFLAGS

export CFLAGS=-Wno-deprecated-declarations

OSX + Brew

PHP

Brew deliberately doesn't expose the OpenSSL package to avoid programs finding it by accident, so to get PHP to find it you need to do something like:

export PKG_CONFIG_PATH="/opt/homebrew/Cellar/openssl@1.1/1.1.1s/lib/pkgconfig:$PKG_CONFIG_PATH"

ImageMagick apparently has difficulty locating the JPEG libraries installed by Brew. Although I'm sure you can pass their location 'properly', you can also do it by hard-coding them in your bash (or ZSH) shell settings.

cat ~/.zshrc
export PATH="/opt/homebrew/opt/bison/bin:/opt/danack/bin:/Users/danack/Library/Python/3.9/bin/:$PATH"
export CFLAGS="-I/opt/homebrew/Cellar/jpeg/9e/include -I/opt/danack/include/ImageMagick-7 -I/opt/danack/php"
export CPPFLAGS="-I/opt/homebrew/Cellar/jpeg/9e/include -I/opt/danack/include/ImageMagick-7 -I/opt/danack/php"
export LDFLAGS="-L/opt/homebrew/Cellar/jpeg/9e/lib -ljpeg"

You probably don't want to install PHP into a system directory, as that requires super-user permissions. Instead of that, you can configure PHP with --prefix and --exec-prefix pointing to somewhere in the /opt directory, and add the relevant bin paths to the PATH variable:

./configure \
  --enable-mbstring \
  --without-iconv \
  --with-curl \
  --disable-phpdbg \
  --prefix=/opt/danack \
  --exec-prefix=/opt/danack \
  --with-openssl \
  --enable-debug \
  --enable-debug-assertions

ImageMagick

./configure \
  --disable-docs \
  --with-quantum-depth=16 \
  --with-fftw \
  --with-fontconfig=yes \
  --with-jpeg=yes \
  --with-magick-plus-plus=no \
  --with-png=yes \
  --with-tiff=yes \
  --with-webp=yes \
  --without-perl \
  --without-zstd \
  --enable-hdri=yes \
  --prefix=/opt/danack \
  --exec-prefix=/opt/danack

Delegate library configuration:
  BZLIB             --with-bzlib=yes		yes
  Autotrace         --with-autotrace=no		no
...
  HEIC              --with-heic=yes		no
  JBIG              --with-jbig=yes		no
  JPEG v1           --with-jpeg=yes		yes
  JPEG XL           --with-jxl=yes		no
...
  PERL              --with-perl=no		no
  PNG               --with-png=yes		yes
...
  TIFF              --with-tiff=yes		no
  WEBP              --with-webp=yes		yes