pin-depends pinning speed

[NathanReb]

I recently tried to opam install a local package with every dependency pinned via the pin-depends field in its opam file and the opam install is significantly slowed down by the initial pinning process.

I tried the 2.1 alpha hoping it might have been improved by recent changes but it seems to have no effect.

Do you have any idea why this takes so long and/or if this can be easily improved? I suspect that cloning the repositories is what takes up most of the time but I also imagine running those in parallel could improve the situation.

[NathanReb]

cc @avsm

[NathanReb]

If you want to give this a try, here's the opam file that I used:

opam-version: "2.0"
synopsis: "duniverse generated lockfile"
maintainer: "duniverse"
depends: [
  "alcotest" {= "1.2.1"}
  "astring" {= "0.8.4+dune"}
  "cmdliner" {= "1.0.4+dune"}
  "cppo" {= "1.6.6"}
  "dune-configurator" {= "2.6.2"}
  "dune-private-libs" {= "2.6.2"}
  "findlib" {= "1.8.1+dune"}
  "fmt" {= "0.8.8+dune"}
  "fpath" {= "0.7.2+dune"}
  "logs" {= "0.7.0+dune"}
  "lwt" {= "5.3.0"}
  "mmap" {= "1.1.0"}
  "ocaml-migrate-parsetree" {= "1.7.3"}
  "ocaml-version" {= "2.6.1"}
  "ocamlfind" {= "1.8.1+dune"}
  "ocplib-endian" {= "1.1"}
  "odoc" {= "1.5.1"}
  "ppx_derivers" {= "1.2.1"}
  "re" {= "1.9.0"}
  "result" {= "1.5"}
  "seq" {= "base+dune"}
  "stdlib-shims" {= "0.1.0"}
  "tyxml" {= "4.4.0"}
  "uuidm" {= "0.9.7+dune"}
  "uutf" {= "1.0.2+dune"}
]
pin-depends: [
  [
    "alcotest.1.2.1"
    "git+https://github.com/mirage/alcotest.git#6ca7cc04ea07f5bd5b001fed4a0313d82e4b3cc0"
  ]
  [
    "astring.0.8.4+dune"
    "git://github.com/dune-universe/astring.git#baa4e7e2bf919293aac2c899786c2ac40757dd9b"
  ]
  [
    "cmdliner.1.0.4+dune"
    "git://github.com/dune-universe/cmdliner.git#4fc08affe26642b6285cedc1d2ca7ec03127caf3"
  ]
  [
    "cppo.1.6.6"
    "git+https://github.com/ocaml-community/cppo.git#51c598bf4a4732fdd9be1b16a5b26743ec4023d2"
  ]
  [
    "dune-configurator.2.6.2"
    "git+https://github.com/ocaml/dune.git#3e37ed0de8c57b7c59db9e1a5c3cf7aca4904430"
  ]
  [
    "dune-private-libs.2.6.2"
    "git+https://github.com/ocaml/dune.git#3e37ed0de8c57b7c59db9e1a5c3cf7aca4904430"
  ]
  [
    "findlib.1.8.1+dune"
    "git+https://github.com/dune-universe/lib-findlib#55b3374114ea425e8881e4758a06b02ba06aabb5"
  ]
  [
    "fmt.0.8.8+dune"
    "git+https://github.com/dune-universe/fmt#342fa6d95e847694b71f798ad55cb932b64d0d35"
  ]
  [
    "fpath.0.7.2+dune"
    "git://github.com/dune-universe/fpath.git#9402e6033c994ab3201be04c6f8e8a101e737ab9"
  ]
  [
    "logs.0.7.0+dune"
    "git://github.com/dune-universe/logs.git#4f141048f71b1d84b8e283086c62ca270aa13051"
  ]
  [
    "lwt.5.3.0"
    "git+https://github.com/ocsigen/lwt.git#ba43d08a484774545428fd9e5a7ba6a8fbb6440a"
  ]
  [
    "mmap.1.1.0"
    "git+https://github.com/mirage/mmap.git#46f613db11c00667764523ccbb3d63e53e1c666c"
  ]
  [
    "ocaml-migrate-parsetree.1.7.3"
    "git+https://github.com/ocaml-ppx/ocaml-migrate-parsetree.git#c5d4f6fce30d3eb699d79d288d0b265752ba64c5"
  ]
  [
    "ocaml-version.2.6.1"
    "git+https://github.com/ocurrent/ocaml-version.git#c1a46982e15b89bd07b304c7c3784496e2341d5f"
  ]
  [
    "ocamlfind.1.8.1+dune"
    "git+https://github.com/dune-universe/lib-findlib#55b3374114ea425e8881e4758a06b02ba06aabb5"
  ]
  [
    "ocplib-endian.1.1"
    "git+https://github.com/OCamlPro/ocplib-endian.git#6ee41bb7f8f2bef103bcf4e05ace57597c0d2316"
  ]
  [
    "odoc.1.5.1"
    "git+https://github.com/ocaml/odoc.git#b794961f43fa34c835e4bd21d2c76a734bfbe7bd"
  ]
  [
    "ppx_derivers.1.2.1"
    "git://github.com/ocaml-ppx/ppx_derivers.git#d6655353f647d33de12d215aaa477ba936febef3"
  ]
  [
    "re.1.9.0"
    "git+https://github.com/ocaml/ocaml-re.git#42c7f8899c9b1a4e011053487a97cf7eab312d5f"
  ]
  [
    "result.1.5"
    "git+https://github.com/janestreet/result.git#b0b9cd6e9cce8d2b7ad11127a6135540ec3f8a92"
  ]
  [
    "seq.base+dune"
    "git+https://github.com/c-cube/seq.git#6934813195285661cba3e017e7d3cd79d362bb2f"
  ]
  [
    "stdlib-shims.0.1.0"
    "git+https://github.com/ocaml/stdlib-shims.git#d32f70e5bec8255903e9b27f89c49da812ad9b6e"
  ]
  [
    "tyxml.4.4.0"
    "git+https://github.com/ocsigen/tyxml.git#35435ed1ed2424119da82c794aa9ad0fbfeddd9f"
  ]
  [
    "uuidm.0.9.7+dune"
    "git://github.com/dune-universe/uuidm.git#fa124fd3c0a82f7005fdac982e520c9c066488c4"
  ]
  [
    "uutf.1.0.2+dune"
    "git://github.com/dune-universe/uutf.git#66ddef1cf88fa0806095fb262b3a47b32a85b54d"
  ]
]

[rjbou]

Thanks for the very good example!