Installation Fail On MacOS about sfnetworks

[harryprince]

This issue is due to the low version of sf, after upgrade sf package, sf::sf_extSoftVersion()["PROJ"] return is not NA

[agila5]

Hi @harryprince and thanks for your message.

@luukvdmeer I just noticed that sf::sf_extSoftVersion()["PROJ"] is defined only for sf >= 1.0 (see r-spatial/sf@9aa8a62#diff-1e8c7b94d7dc2f0d70c4e457124889b5637ba42993015643e5d80be52e3ec912), and the package loading fails for older versions (at least on windows):

remotes::install_version("sf", "0.9.8", quiet = TRUE)
remotes::install_cran("sfnetworks", quiet = TRUE)
library(sfnetworks)
#> Registered S3 method overwritten by 'spatstat.geom':
#>   method     from
#>   print.boxx cli
#> Error: package or namespace load failed for 'sfnetworks':
#>  .onAttach failed in attachNamespace() for 'sfnetworks', details:
#>   call: if (sf::sf_extSoftVersion()["PROJ"] < "6.0.0" || sf::sf_extSoftVersion()["proj.4"] < 
#>   error: missing value where TRUE/FALSE needed

^{Created on 2022-01-03 by the reprex package (v2.0.1)}

I think we should slightly adjust the following if-clause:

sfnetworks/R/zzz.R

Lines 89 to 90 in 28cbfb8

	.onAttach = function(libname, pkgname) {
	if (sf::sf_extSoftVersion()["PROJ"] < "6.0.0" || sf::sf_extSoftVersion()["proj.4"] < "6.0.0") {

with something like:

 .onAttach = function(libname, pkgname) { 
   if (sf::sf_extSoftVersion()["proj.4"] < "6.0.0") { 

I'm not 100% sure it is safe to ignore the output of sf::sf_extSoftVersion()["PROJ"], but it looks like it returns the same value as sf::sf_extSoftVersion()["proj.4"]. If you agree, I can create a PR.