How do I change directory in macports Portfile and run a Makefile

Trying to add a Portfile to Macports via this draft PR and can't figure out how I change directory in post-extract.

The Portfile looks like this right now:

# -*- coding: utf-8; mode: tcl; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- vim:fenc=utf-8:ft=tcl:et:sw=4:ts=4:sts=4

PortSystem          1.0
PortGroup           github 1.0
PortGroup           cargo  1.0

github.setup        DominikWilkowski cfonts 1.0.2rust v
revision            0

categories          textproc
license             GPL-3+
maintainers         {DominikWilkowski @DominikWilkowski}

description         Sexy ANSI fonts for the console
long_description    This is a silly little command line tool for sexy fonts in the console. \
                    Give your cli some love.
homepage            https://github.com/dominikwilkowski/cfonts

checksums           ${distfiles} \
                    rmd160  6f5bedcb0e1cb54faf9efb2b4e34dbe6105152ea \
                    sha256  33c14dda907c4f3c046a40644c8856f6debb87b58ee6fbaab2b8d7af14ce8b6e \
                    size    3312272

post-extract {
    cd rust/
}

destroot {
    xinstall -m 755 ${worksrcpath}/target/[cargo.rust_platform]/release/${name} \
        ${destroot}${prefix}/bin/
}

In the repo the rust source code is in the /rust folder which means I have to go into that folder before running cargo build (which I assume the Portgroup does for you). I also need to run the Makefile before building as it moves artifacts into the right place.

I find the docs very sparse and it seems difficult to google this issue.

Looking at other Portfiles I also notice that rust packages mention the dependencies and their hashes... Any help is appreciated.

Solution

Ok I had a lot of help with this in the PR.

The answers boil down to this:

How to change directory:

build.dir           ${worksrcpath}/rust

How to run a Makefile (within a sub-folder):

pre-build {
    system          -W ${worksrcpath}/rust "make"
}

How to link it all in the end:

destroot {
    xinstall -m 0755 ${worksrcpath}/rust/target/[cargo.rust_platform]/release/${name} \
        ${destroot}${prefix}/bin/
}

And how to create the dependencies and their hashes: There is a port called cargo2port that uses the Cargo.lock file and generates the output for you.

So with all that the final Portfile is:

# -*- coding: utf-8; mode: tcl; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- vim:fenc=utf-8:ft=tcl:et:sw=4:ts=4:sts=4

PortSystem          1.0
PortGroup           github 1.0
PortGroup           cargo  1.0

github.setup        DominikWilkowski cfonts 1.0.2 v rust
revision            0

categories          textproc
license             GPL-3+
maintainers         {DominikWilkowski @DominikWilkowski} \
                    openmaintainer

description         Sexy ANSI fonts for the console
long_description    This is a silly little command line tool for sexy fonts in the console. \
                    Give your cli some love.

checksums           ${distfiles} \
                    rmd160  6f5bedcb0e1cb54faf9efb2b4e34dbe6105152ea \
                    sha256  33c14dda907c4f3c046a40644c8856f6debb87b58ee6fbaab2b8d7af14ce8b6e \
                    size    3312272

build.dir           ${worksrcpath}/rust

pre-build {
    system          -W ${worksrcpath}/rust "make"
}

destroot {
    xinstall -m 0755 ${worksrcpath}/rust/target/[cargo.rust_platform]/release/${name} \
        ${destroot}${prefix}/bin/
}

cargo.crates \
    atty                            0.2.14  d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8 \
    cfg-if                           1.0.0  baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd \
    enable-ansi-support              0.1.2  28d29d3ca9ba14c336417f8d7bc7f373e8c16d10c30cc0794b09d3cecab631ab \
    exitcode                         1.1.2  de853764b47027c2e862a995c34978ffa63c1501f2e15f987ba11bd4f9bba193 \
    getrandom                        0.2.6  9be70c98951c83b8d2f8f60d7065fa6d5146873094452a1008da8c2f1e4205ad \
    heck                             0.4.0  2540771e65fc8cb83cd6e8a237f70c319bd5c29f78ed1084ba5d50eeac86f7f9 \
    hermit-abi                      0.1.19  62b467343b94ba476dcb2500d242dadbb39557df889310ac77c5d99100aaac33 \
    is_ci                            1.1.1  616cde7c720bb2bb5824a224687d8f77bfd38922027f01d825cd7453be5099fb \
    itoa                             1.0.1  1aab8fc367588b89dcee83ab0fd66b72b50b72fa1904d7095045ace2b0c81c35 \
    libc                           0.2.125  5916d2ae698f6de9bfb891ad7a8d65c09d232dc58cc4ac433c7da3b2fd84bc2b \
    once_cell                       1.10.0  87f3e037eac156d1775da914196f0f37741a274155e34a0b7e427c35d2a2ecb9 \
    ppv-lite86                      0.2.16  eb9f9e6e233e5c4a35559a617bf40a4ec447db2e84c20b55a6f83167b7e57872 \
    proc-macro2                     1.0.37  ec757218438d5fda206afc041538b2f6d889286160d649a86a24d37e1235afd1 \
    quote                           1.0.18  a1feb54ed693b93a84e14094943b84b7c4eae204c512b7ccb95ab0c66d278ad1 \
    rand                             0.8.5  34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404 \
    rand_chacha                      0.3.1  e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88 \
    rand_core                        0.6.3  d34f1408f55294453790c48b2f1ebbb1c5b4b7563eb1f418bcfcfdbb06ebb4e7 \
    rustversion                      1.0.6  f2cc38e8fa666e2de3c4aba7edeb5ffc5246c1c2ed0e3d17e560aeeba736b23f \
    ryu                              1.0.9  73b4b750c782965c211b42f022f59af1fbceabdd026623714f104152f1ec149f \
    serde                          1.0.136  ce31e24b01e1e524df96f1c2fdd054405f8d7376249a5110886fb4b658484789 \
    serde_derive                   1.0.136  08597e7152fcd306f41838ed3e37be9eaeed2b61c42e2117266a554fab4662f9 \
    serde_json                      1.0.79  8e8d9fa5c3b304765ce1fd9c4c8a3de2c8db365a5b91be52f186efc675681d95 \
    strum                           0.24.0  e96acfc1b70604b8b2f1ffa4c57e59176c7dbb05d556c71ecd2f5498a1dee7f8 \
    strum_macros                    0.24.0  6878079b17446e4d3eba6192bb0a2950d5b14f0ed8424b852310e5a94345d0ef \
    supports-color                   1.3.0  4872ced36b91d47bae8a214a683fe54e7078875b399dfa251df346c9b547d1f9 \
    syn                             1.0.91  b683b2b825c8eef438b77c36a06dc262294da3d5a5813fac20da149241dcd44d \
    temp-env                         0.2.0  45107136c2ddf8c4b87453c02294fd0adf41751796e81e8ba3f7fd951977ab57 \
    terminal_size                   0.1.17  633c1a546cee861a1a6d0dc69ebeca693bf4296661ba7852b9d21d159e0506df \
    unicode-xid                      0.2.2  8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3 \
    wasi                          0.10.2+wasi-snapshot-preview1  fd6fbd9a79829dd1ad0cc20627bf1ed606756a7f77edff7b66b7064f9cb327c6 \
    winapi                           0.3.9  5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419 \
    winapi-i686-pc-windows-gnu       0.4.0  ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6 \
    winapi-x86_64-pc-windows-gnu     0.4.0  712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f

I hope it helps someone else later