Updating libcurl

I'm cross-compiling for the Onion Omega2 and need to upgrade the libcurl library to 7.57.

The build directory seems to have a good version of curl:

But then the staging directory is the old version of libcurl:

Apparently, the curl package itself has an old libcurl:

Any advice on how I can update that libcurl?

When compiling the app, I get the following error:

checking for LIBCURL... no
configure: error: Missing required libcurl dev >= 7.18.2

I managed to cross-compile HelloWorld and run it on my device, so I'm hoping if I can get libcurl updated, I can get this app built.

Any suggestions appreciated.

It looks like you don't have the development headers installed. If you're on Debian/Ubuntu, try:
$ sudo apt install libcurl-dev

If that doesn't work, look here for suggestions: