bin: dependencies not working at all?

[Joshua Root]

On 2020-1-31 11:32 , Ken Cunningham wrote:
> Either I’m having a problem understanding bin: deps, or something is not working correctly with them.
> 
> I’ve tried the same thing on several different machines, and always seem to get the same result.
> 
> 
> 
> Specifically, I’m trying to trim down unrequired dependencies on some of the bootstrap ports to minimize headaches and heartburn maintaining them.
> 
> llvm-3.4 for example does not need any special perl.
> 
> In the portfile, it has
> 
>     depends_run         bin:perl:perl5 port:llvm_select
> 
> This means (to me) look for a binary named perl somewhere in the path, and install perl5 if there isn’t one. 
> 
> Of course, there always is a binary named “perl” in the path, so the depends itself is a bit redundant, but at any rate, with all ports uninstalled, the system perl is active:
> 
> $ port -v installed | grep active
> $ which perl
> /usr/bin/perl
> 
> $ printenv
> PATH=/opt/local/bin:/opt/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin
> 
> however, port still wants to install perl5 and all it’s supporting deps:
> 
> $ port info llvm-3.4
> llvm-3.4 @3.4.2_12 (lang)
> Sub-ports:            clang-3.4
> Variants:             assertions, ocaml, universal
> 
> Description:          The LLVM Core libraries provide a modern source- and target-independent optimizer, along with code generation support for many popular CPUs (as well as some less common ones!) These
>                       libraries are built around a well specified code representation known as the LLVM intermediate representation ("LLVM IR").
> Homepage:             https://llvm.org/
> 
> Library Dependencies: libffi, ncurses-bootstrap, zlib
> Runtime Dependencies: perl5, llvm_select
> Platforms:            darwin
> License:              NCSA
> Maintainers:          Email: jeremyhu at macports.org, GitHub: jeremyhu
>                       Email: larryv at macports.org, GitHub: larryv
>                       Email: kencu at macports.org, GitHub: kencu

try 'port -v info' or 'port -v deps'

> $ port rdeps llvm-3.4
> The following ports are dependencies of llvm-3.4 @3.4.2_12:
>   libffi
>   ncurses-bootstrap
>   zlib
>     xz-bootstrap
>       libiconv-bootstrap
>         gperf-bootstrap
>       gettext-bootstrap
>   perl5
>     perl5.28
>       xz
>         clang-3.4
>           cctools
>             libunwind-headers
>             llvm-3.4
>               llvm_select
>           python27-bootstrap
>             pkgconfig-bootstrap
>             bzip2
>             expat
>             openssl
>           clang_select
>           ld64
>             ld64-127
>               libmacho-headers
>         libiconv
>           gperf
>             libcxx
>         gettext
>           ncurses
>       db48
>       gdbm
>         readline

rdeps follows all dependencies and doesn't check whether they're
satisfied by something other than the named port. This is arguably a
good thing since it keeps the output consistent regardless of which
ports you have installed. An option to calculate deps like mportdepends
could be a useful feature to add.

> changing it to a path dependency doesn’t help:
> 
> depends_run         path:bin/perl:perl5

That's a relative path and so looks for bin/perl under ${prefix}
specifically. There's only one port that provides that file.

> $ port info llvm-3.4
> llvm-3.4 @3.4.2_12 (lang)
> ...
> Runtime Dependencies: perl5, llvm_select
> 
> 
> Even sticking a symlink in ${prefix}/bin doesn’t work:
> 
> $ sudo ln -s /usr/bin/perl /opt/local/bin/perl
> 
> $ which perl
> /opt/local/bin/perl
> 
> $ port info llvm-3.4
> llvm-3.4 @3.4.2_12 (lang)
> …
> Runtime Dependencies: perl5, llvm_select
> 
> 
> What stupid assumption am I making, or what am I doing wrong?

When you actually install, the bin: dependency will be considered
satisfied by /usr/bin/perl.

- Josh