cross build error for NetBSD/arm

[yamori813]

I use conf.gembox 'default' on cross build on FreeBSD/amd64 for NetBSD/arm.

I have error no libreadline and no libncurses.

I seem cause of mrbgems/mruby-bin-mirb/mrbgem.rake.

I want use libedit.

Also NetBSD 9.99 libedit need libtermcap.

If you have advice, please let me know.

Thanks

[matz]

Show us the error messages.

[yamori813]

% rake MRUBY_CONFIG=netbsd
LD    build/cross-netbsd-arm/bin/mirb 
/usr/home/hiroki/netbsd-tools/earmv4/lib/gcc/armv4--netbsdelf-eabi/10.4.0/../../../../armv4--netbsdelf-eabi/bin/ld: cannot find -lreadline
/usr/home/hiroki/netbsd-tools/earmv4/lib/gcc/armv4--netbsdelf-eabi/10.4.0/../../../../armv4--netbsdelf-eabi/bin/ld: cannot find -lncurses
collect2: error: ld returned 1 exit status
rake aborted!
Command failed with status (1): [/usr/home/hiroki/netbsd-tools/earmv4/bin/a...]
/usr/home/hiroki/mruby-3.1.0/lib/mruby/build/command.rb:37:in `_run'
/usr/home/hiroki/mruby-3.1.0/lib/mruby/build/command.rb:217:in `run'
/usr/home/hiroki/mruby-3.1.0/tasks/bin.rake:17:in `block (4 levels) in <top (required)>'
/usr/home/hiroki/mruby-3.1.0/Rakefile:42:in `block in <top (required)>'
Tasks: TOP => build => /usr/home/hiroki/mruby-3.1.0/build/cross-netbsd-arm/bin/mirb
(See full trace by running task with --trace)

[dearblue]

I don't know if this is correct, but how about replacing the library by calling mruby-bin-mirb with a block before gembox "default", as in the following example?

MRuby::CrossBuild.new("netbsd") do |conf|
  conf.toolchain "gcc"
  conf.gem core: "mruby-bin-mirb" do |spec|
    spec.linker.libraries = %w(edit termcap)
  end
  conf.gembox "default"
end

---

mruby-bin-mirb cannot automatically cross build to/from NetBSD for reasons determined by RUBY_PLATFORM.

mruby/mrbgems/mruby-bin-mirb/mrbgem.rake

Lines 21 to 24 in 1bec339

	if RUBY_PLATFORM.include?('netbsd')
	spec.linker.libraries << 'edit'
	else
	spec.linker.libraries << 'readline'

Some improvement is needed, but I have no ideas.

[yamori813]

This replacing workaround is fine on my environment.

[yamori813]

Same problem on this case.

https://qiita.com/yamori813/items/5153efb2ec0a23bfa7fb

I think good that is RUBY_PLATFORM set "NetBSD" at build_config. And use is value in mrbgem.rake. But RUBY_PLATFORM is confuse host and target now.

[matz]

Probably, we need to distinguish host and target during the build (and use target info instead of RUBY_PLATFORM).

[dearblue]

The RUBY_PLATFORM constant is defined by Ruby, so I don't think it is desirable to make any changes to it.
I also think that introducing another constant to check the build target is undesirable, as it leads to writing code that assumes the environment to be a prerequisite by name.

How about introducing methods for "feature check" (such as have_library or have_macro) defined in Ruby's mkmf.rb library?
However, I would like to have a mechanism to avoid this, since there is a possibility that these methods will be called every time just by rake clean, for example.

Example?:

# mygem/mrbgem.rake
MRuby::Gem::Specification.new("mygem") do |spec|
  ....
  spec.before_compile do
    case
    when spec.have_library "edit"
      ....
    when spec.have_library "readline"
      ....
    else
      ....
    end
  end
end