Bug#814720: r-cran-httpuv: FTBFS: dependency 'Rcpp' is not available

[Aaron M. Ucko]

Source: r-cran-httpuv
Version: 1.3.3-2
Severity: serious
Justification: fails to build from source

Builds of r-cran-httpuv in minimal environments (notably, on the
autobuilders) have been failing:

  ERROR: dependency 'Rcpp' is not available for package 'httpuv'
  * removing '/«PKGBUILDDIR»/debian/r-cran-httpuv/usr/lib/R/site-library/httpuv'
  /usr/share/R/debian/r-cran.mk:98: recipe for target 'R_any_arch' failed
  make: *** [R_any_arch] Error 1

Please declare a build dependency on r-cran-rcpp and confirm with
pbuilder or the like that you haven't missed any others.

Thanks!