ifeq error in `make home-install` target

[bufordrat]

Currently, the home-install target is throwing the following error on sequent (Matt's Arch Linux box.)

> make home-install
dune build --display short
dune install --display short
Deleting /home/teichman/.opam/4.14.1/lib/attachment-converter/META
Installing /home/teichman/.opam/4.14.1/lib/attachment-converter/META
Deleting /home/teichman/.opam/4.14.1/lib/attachment-converter/dune-package
Installing /home/teichman/.opam/4.14.1/lib/attachment-converter/dune-package
Deleting /home/teichman/.opam/4.14.1/lib/attachment-converter/opam
Installing /home/teichman/.opam/4.14.1/lib/attachment-converter/opam
Deleting /home/teichman/.opam/4.14.1/bin/attachment-converter
Installing /home/teichman/.opam/4.14.1/bin/attachment-converter
Deleting /home/teichman/.opam/4.14.1/doc/attachment-converter/LICENSE
Installing /home/teichman/.opam/4.14.1/doc/attachment-converter/LICENSE
Deleting /home/teichman/.opam/4.14.1/doc/attachment-converter/README.org
Installing /home/teichman/.opam/4.14.1/doc/attachment-converter/README.org
ifeq [pacman --version]
libreoffice pandoc ghostscript libvips
else
libreoffice pandoc ghostscript vips verapdf
endif
echo Cloning attc git repo...
cd ~
mkdir attachment-converter
cd attachment-converter
git clone https://github.com/uchicago-library/attachment-converter.git
echo Copying shell scripts...
cd ~/attachment-converter
mkdir -p ~/.config/attachment-converter/scripts
cp conversion-scripts/*.sh ~/.config/attachment-converter/scripts
echo Installing to ~/bin/attc...
cp /home/teichman/.opam/4.14.1/bin/attachment-converter ~/bin/attc
ls -lh ~/bin/attc
echo Attachment Converter has been installed to ~/bin/attc.
echo Please ensure that ~/bin is on your path.
bash: line 1: ifeq: command not found
make: *** [GNUmakefile:85: home-install] Error 127

For this issue, see if you can:

a) reproduce the error on macOS b) amend the code for the home-install target so that it works on both macOS and Linux platforms