This document describes how curl was packaged for build2. In particular, this
understanding will be useful when upgrading to a new upstream version. See
../README-DEV for general notes on curl packaging.

Symlink the required upstream directories into curl/:

$ ln -s ../../upstream/{src,lib} curl
$ ln -s lib/{strtoofft,nonblock,warnless,dynbuf,version_win32,curl_multibyte,base64}.c curl
$ ln -s ../../libcurl/libcurl/curl_config.h curl

Patch curl to use CA certificate bundle provided by the
libca-certificates-curl package by default:

$ cp curl/src/tool_main.c curl/tool_main.c.orig
$ cp curl/src/tool_main.c curl
$ git apply curl/tool_main.c.patch

Note that the above patch is produced by the following command:

$ git diff >curl/tool_main.c.patch