This bird was seen twice in the same spot on the trail, and seemed hesitant to leave. Perhaps a nest was nearby.
The Lyre-tailed Nightjar is the one expected (by me) in San Sebastian, but this bird has white edges to the wing tips, and that is not part of the description on HBW (although immatures are not described) or any photo I can find. Common Nighthawk and Swallow-tailed Nightjar do have that edge. Nor does it have the rufous nape sometimes described as a way to identify the species. Nick Athanas thinks it is a Swallow-tailed Nightjar, and that makes sense. I am not sure the pale wingtip edge is a way to identify nightjar species, but the coloration and lack of rufous collar/nape point to Swallow-tailed.
Africa (entire continent rather than south of Sahara)
AN
Antarctica
AO
Atlantic Ocean
AU
Australasia (Wallacea (Indonesian islands east of Wallace's line), New Guinea and its islands, Australia, New Zealand and its subantarctic islands, the Solomons, New Caledonia, and Vanuatu)
PAL
Eurasia (Europe, Asia from the Middle East through central Asia north of the Himalayas, Siberia and northern China to Japan)
IO
Indian Ocean
LA
Latin America (Middle and South America)
MA
Middle America (Mexico through Panama)
NA
North America (includes the Caribbean)
NO
Northern oceans
OR
Oriental Region (South Asia from Pakistan to Taiwan, plus Southeast Asia, the Philippines, and Greater Sundas)