rPackages.rJava: set JAVA_HOME, fixes darwin

[b-rodrigues]

Sets JAVA_HOME as it was empty. This was not an issue on linux, but caused rPackages.rJava not to load on Darwin.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 24.11 Release Notes (or backporting 23.11 and 24.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

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[b-rodrigues]

@ofborg build rPackages.rJava

[Kupac]

Other than that, it works on x86_64-linux.

It's a bit weird that it doesn't work on darwin despite the explicit export JAVA_HOME. Is that the traditional way to set enc vars on darwin? do the other packages that manupulate JAVA_HOME work on darwin?

[ins] r$> library(rJava)

[ins] r$> example(.jcompare)

.jcmprr$> ## Don't show: 
.jcmprr$> .jinit()

.jcmprr$> ## End(Don't show)
.jcmprr$> s <- .jnew("java/lang/String", "foo")

.jcmprr$> .jequals(s, "foo") # TRUE
[1] TRUE

.jcmprr$> .jequals(s, "foo", strict=TRUE) # FALSE - "foo" is not a Java object
[1] FALSE

.jcmprr$> t <- s

.jcmprr$> .jequals(s, t, strict=TRUE) # TRUE
[1] TRUE

.jcmprr$> s=="foo" # TRUE
[1] TRUE

.jcmprr$> ## Don't show: 
.jcmprr$>  
.jcmprr$> 	stopifnot( 
.jcmpr+ 		.jequals(s, "foo"), 
.jcmpr+ 		!.jequals(s, "foo", strict=TRUE), 
.jcmpr+ 		.jequals(s, t, strict=TRUE), 
.jcmpr+ 		s == "foo"
.jcmpr+ 	)

.jcmprr$> ## End(Don't show)
.jcmprr$> 
.jcmprr$> Double <- J("java.lang.Double")

.jcmprr$> d1 <- new( Double, 0.0 ) 

.jcmprr$> d2 <- new( Double, 1.0 )

.jcmprr$> d3 <- new( Double, 0.0 )

.jcmprr$> d1 < d2
[1] TRUE

.jcmprr$> d1 <= d3
[1] TRUE

.jcmprr$> d1 >= d3
[1] TRUE

.jcmprr$> d1 > d2
[1] FALSE

.jcmprr$> # cannot compare a Double and a String
.jcmprr$> try( d1 < "foo" )
Error in .jcall("RJavaComparator", "I", "compare", .jcast(a), .jcast(b)) : 
  NotComparableException: objects of class java.lang.Double and java.lang.String are not comparable

.jcmprr$> # but can compare a Double and an Integer
.jcmprr$> d1 < 10L
[1] TRUE

.jcmprr$> ## Don't show: 
.jcmprr$> 	stopifnot( 
.jcmpr+ 		d1 < d2       ,
.jcmpr+ 		d1 <= d3      ,
.jcmpr+ 		d1 >= d3      ,
.jcmpr+ 		! (d1 > d2 )  , 
.jcmpr+ 		inherits( try( d1 < "foo", silent = TRUE ), "try-error" ), 
.jcmpr+ 		d1 < 10L )

.jcmprr$> ## End(Don't show)
.jcmprr$> 
.jcmprr$> 
.jcmprr$> 
.jcmprr$> 
.jcmprr$> 

[ins] r$> Sys.getenv("JAVA_HOME")
[1] "/nix/store/3vhlpdyqkrwk9arf84iaxk935r71rxvx-openjdk-21.0.5+11"

[TomaSajt]

I'm surprised it even worked with the env-var only being set at build time.
(I haven't looked at the code, maybe its expected to work like that)

[Kupac]

Sorry, forgot to click submit review... Anyway it's merged now and after all, it's working.

[Kupac]

This belongs to postPatch.