[FIXED] How to install dependencies for a project that is being cross-compiled on an x86 host for an arm target

Issue

I'm trying to build a project (https://wpewebkit.org/) on Debian Buster for armv7 on a x86 host of the same OS.

I am able to successfully install an arm C++ toolchain and I can successfully compile and run trivial applications.

Where I'm stuck is many of the projects I want to compile require many dependencies that I normally install through the OS's package manager (ex apt-get install libjpeg-dev). When cross compiling, it looks like I can just download & make install the sources I need. However, this project has hundreds of dependencies - it would take a long time to download and compile all of them. At the same time, the arm versions of these dependencies already exist in apt for arm.

How can I, on the host system, install the armhf versions of these dependencies and make them available to my cross compiling toolchain? I've tried dpkg add-architecture armhf and then installing via apt-get install libjpeg-dev:armhf but cmake can't seem to find the installed dependencies.

Solution

@artless-noise guides were a good jumping off point, but unfortunately most of the guides weren't helpful in accomplishing what I wanted to do (or if they were, they weren't straightforward in explaining how to accomplish what I needed).

What I ended up doing was using qemu-debootstrap

sudo qemu-debootstrap --arch armhf buster /mnt/data/armhf http://deb.debian.org/debian/

And then just using sudo chroot /mnt/data/armhf and I had a functioning shell where I could just apt-get anything I needed, run any scripts and get armhf binaries.

Answered By - killachaos

Answer Checked By - Robin (PHPFixing Admin)