“If you remove stricture from a large Perl program currently, you're just installing delayed bugs, whereas with this feature, you're installing an instant bug that's easily fixed. Whoopee.”
[199710050130.SAA04762@wall.org, 1997]
Usenet postings, 1997
Help us to complete the source, original and additional information
Larry Wall 294
American computer programmer and author, creator of Perl 1954Related quotes
“…perhaps this is a "feature", not a bug….”
1995/10
About Microsoft
“"The question is, is that a bug or a feature?" Karl asked.”
The Wizardry Compiled (1989)

"The Free Software Movement and the GNU/Linux Operating System", address at LinuxTag (July 2000)
2000s

“That is a known bug in 5.00550. Either an upgrade or a downgrade will fix it.”
[6vu1vo%2489c@kiev.wall.org, 1998]
Usenet postings, 1998

“In other words, crew deaths are a feature, not a bug," Cassaway said, dryly.”
Source: Redshirts

Nicholas Negroponte: A 30-year history of the future http://www.ted.com/talks/nicholas_negroponte_a_30_year_history_of_the_future, July 2014, TED Talks (about 13:40 into 19:43 video).
A 30-year history of the future, TED Talk (2014)

Focus Magazine No. 43 (23 October 1995) http://www.cantrip.org/nobugs.html <!-- pages 206-212 -->
1990s

“Program testing can be used to show the presence of bugs, but never to show their absence!”
Dijkstra (1970) " Notes On Structured Programming http://www.cs.utexas.edu/users/EWD/ewd02xx/EWD249.PDF" (EWD249), Section 3 ("On The Reliability of Mechanisms"), corollary at the end.
1970s
Variant: Program testing can be a very effective way to show the presence of bugs, but it is hopelessly inadequate for showing their absence.