Error(s) in re-building vignettes:
--- re-building ‘FRK_intro.Rnw’ using knitr

Attaching package: 'dplyr'

The following objects are masked from 'package:stats':

    filter, lag

The following objects are masked from 'package:base':

    intersect, setdiff, setequal, union

Note: show_basis assumes spherical distance functions when plotting
Loading required namespace: gstat
OMP: Warning #96: Cannot form a team with 8 threads, using 2 instead.
OMP: Hint Consider unsetting KMP_DEVICE_THREAD_LIMIT (KMP_ALL_THREADS), KMP_TEAMS_THREAD_LIMIT, and OMP_THREAD_LIMIT (if any are set).
Warning in showSRID(uprojargs, format = "PROJ", multiline = "NO", prefer_proj = prefer_proj) :
  Discarded datum Unknown based on Normal Sphere (r=6370997) ellipsoid in Proj4 definition
Loading required namespace: rgeos
Warning in RGEOSUnaryPredFunc(spgeom, byid, "rgeos_isvalid") :
  Self-intersection at or near point 32.063945725862894 -87.550066691193749
prob_polys2_sp[i, ] is invalid
Warning in rgeos::gIntersection(prob_polys2_sp[i, ], line) :
  Invalid objects found; consider using set_RGEOS_CheckValidity(2L)
Input geom 0 is INVALID: Self-intersection at or near point 32.063945725862894 -87.550066691193749 (32.06394572586289371 -87.550066691193748625)
<A>
POLYGON ((63.5835269999999966 -88.0237999999999943, 53.4685389999999998 -87.9624799999999993, 44.2134789999999995 -87.8425660000000050, 36.1185320000000019 -87.6731709999999964, 29.2376359999999984 -87.4642549999999943, 20.4793470000000006 -87.5580929999999995, 11.2499909999999996 -87.5912090000000063, 2.0206320000000000 -87.5580929999999995, 353.2623419999999896 -87.4642560000000060, 346.3814429999999902 -87.6731719999999939, 338.2864930000000072 -87.8425660000000050, 329.0314319999999952 -87.9624799999999993, 318.9164440000000127 -88.0237999999999943, 314.7319309999999746 -88.3587859999999949, 308.4641730000000166 -88.6805130000000048, 298.3904769999999758 -88.9765780000000035, 281.2499750000000063 -89.2175160000000034, 281.2499500000000126 -89.6086370000000016, 320.1237770000000182 -89.9999990000000025, 101.2499499999999983 -89.6086379999999991, 101.2499750000000063 -89.2175170000000008, 84.1094729999999942 -88.9765780000000035, 74.0357850000000042 -88.6805130000000048, 67.7680340000000001 -88.3587859999999949, 63.5835269999999966 -88.0237999999999943))
</A>
Warning in proj4string(x) :
  CRS object has comment, which is lost in output; in tests, see
https://cran.r-project.org/web/packages/sp/vignettes/CRS_warnings.html
Warning in proj4string(BAUs) :
  CRS object has comment, which is lost in output; in tests, see
https://cran.r-project.org/web/packages/sp/vignettes/CRS_warnings.html
Warning in proj4string(sp_pols) :
  CRS object has comment, which is lost in output; in tests, see
https://cran.r-project.org/web/packages/sp/vignettes/CRS_warnings.html
Warning in proj4string(obj) :
  CRS object has comment, which is lost in output; in tests, see
https://cran.r-project.org/web/packages/sp/vignettes/CRS_warnings.html