Bahian Nightjar as originally described in the genus Chordeiles was generically misplaced.  In the booklet that comes with the CD A Sound Guide to Nightjars and Related Nightbirds, Ranft and Cleere state: "Chordeiles veilliardi (Lencioni-Neto 1995) was erroneously described in that genus.

It is clearly a member of the genus Nyctiprogne, as documented by Bret M. Whitney, José Fernando Pacheco, Paulo Sérgio Moreira da Fonseca, and Richard E. Webster near Januária, Minas Gerais, in November 1995" (B.M. Whitney in litt., January 1998)

Bahian Nighthawk     Nyctiprogne vielliardi
Brazil: Bahia state
insert after: Nyctiprogne leucopyga
Frederico Lencioni-Neto,
Une nouvelle espčce de Chordeiles (Aves, Caprimulgidae) de Bahia (Brésil)
Alauda 62, 4 (1994): 241-245

To my knowledge, no other specimens have since been observed, let alone photographed or collected. The specific scientific name (solala) of Nechisar Nightjar means "single-winged" . . .

Doubts have been cast on the validity of this taxon, as can be expected when a species is described from not even half a bird.  Forero & Tella (Sexual dimorphism, plumage variability and species determination in nightjars: the need for further examination of the Nechisar Nightjar Caprimulgus solala, Ibis 1997: 407-409) provide illustrations of high variability of characters within a single species (C. ruficollis), and point out that extreme care should be taken.

Nechisar Nightjar     Caprimulgus solala
Ethiopia: Nechisar Plains, Gamo Gofa province
insert after: Caprimulgus natalensis
R.J. Safford, J.S. Ash, J.W. Duckworth, M.G. Telfer & C. Zewdie,
A new species of nightjar from Ethiopia
Ibis 137, 3 (1995): 301-307