UNLESS you add an "exception" clause to the fossil license. Many programs have such an exception clause, e.g., wget has one, which I include below. (This is an FSF-approved thing to do, BTW; the wording below is the wording the FSF uses when they add such a clause, and which they have recommended to others.)

"In addition, as a special exception, the Free Software Foundation gives permission to link the code of its release of Wget with the OpenSSL project's "OpenSSL" library (or with modified versions of it that use the same license as the "OpenSSL" library), and distribute the linked executables. You must obey the GNU General Public License in all respects for all of the code used other than "OpenSSL". If you modify this file, you may extend this exception to your version of the file, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version."

If the above is unclear (or unconvincing!) please do not hesitate to email. -- Barak A. Pearlmutter <barak@cs.nuim.ie>