I am trying to use libcurl in a program.

I am cross compiling this program for the Omega 1 on my laptop using the official guide.

I am having issues figuring out how to obtain the header files and the library for libcurl on the Omega 1 for cross compilation.

Issues

If I compile the program for my host OS then my native toolchain will find the necessary libcurl files. I am not sure if these same files can be used to cross compile a program for the Omega 1.

I can use opkg to install libcurl on the Omega. However I believe I need the files on my laptop instead.

If I try to install the libcurl package on my laptop inside the OpenWRT git repository by running:

scripts/feeds update -a
scripts/feeds install libcurl

It does not seem to work for 2 reasons.

First because that the install command shows this output:

WARNING: Makefile 'package/network/utils/curl/Makefile' has a dependency on 'libgnutls', which does not exist
WARNING: Makefile 'package/network/utils/curl/Makefile' has a dependency on 'libopenldap', which does not exist
WARNING: Makefile 'package/network/utils/curl/Makefile' has a dependency on 'libidn2', which does not exist
WARNING: Makefile 'package/network/utils/curl/Makefile' has a dependency on 'libssh2', which does not exist
WARNING: Makefile 'package/boot/kexec-tools/Makefile' has a dependency on 'liblzma', which does not exist
WARNING: Makefile 'package/network/services/lldpd/Makefile' has a dependency on 'libnetsnmp', which does not exist
WARNING: Makefile 'package/network/utils/nftables/Makefile' has a dependency on 'jansson', which does not exist

And second because the cross compile toolchain still can't find the curl/curl.h.

Question

How would I go about obtaining the files needed to cross compile a binary for the Omega 1 with libcurl?

On the omega itself, you can just copy the .so library files from your buildroot into /usr/lib (or wherever you want to keep them)

I’ve done this with several libs.

I figured this out myself, so hopefully it's all correct. But it works

1. Make sure your shell is in the source directory
2. Run: "./scripts/feeds install <<your lib>>"
3. Often this works. If it doesn't we will install manually.
4. mkdir -p package/libs/<<your lib>>
5. cd package/libs/<<your lib>>
6. wget https://raw.githubusercontent.com/openwrt/packages/master/libs/<<your lib>>/Makefile
7. cd ../../../
8. make package/libs/<<your-lib>>/compile
9. make package/libs/<<your-lib>>/install
10. make package/libs/<<your-lib>>/clean

More information here:
https://openwrt.org/docs/guide-developer/build-system/start

Secondly, this may be a cleaner way to do it, but I haven't tried:
https://navneetstudynotes.blogspot.com/2015/04/building-new-package-with-openwrt.html