[Rd] gfortran 9 quantreg bug

[Koenker, Roger W]

I’d like to solicit some advice on a debugging problem I have in the quantreg package.
Kurt and Brian have reported to me that on Debian machines with gfortran 9

library(quantreg)
f = summary(rq(foodexp ~ income, data = engel, tau = 1:4/5))
plot(f)

fails because summary() produces bogus estimates of the coefficient bounds.
This example has been around in my R package from the earliest days of R, and
before that in various incarnations of S.  The culprit is apparently rqbr.f which is
even more ancient, but must have something that gfortran 9 doesn’t approve of.

I note that in R-devel there have been some other issues with gfortran 9, but these seem
unrelated to my problem.  Not having access to a machine with an R/gfortran9
configuration, I can’t  apply my rudimentary debugging methods.  I’ve considered
trying to build gfortran on my mac air and then building R from source, but before
going down this road, I wondered whether others had other suggestions, or
advice about  my proposed route.  As far as I can see there are not yet
binaries for gfortran 9 for osx.

Thanks,
Roger

Roger Koenker
r.koenker using ucl.ac.uk<mailto:r.koenker using ucl.ac.uk>
Department of Economics, UCL
London  WC1H 0AX.



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