Opam doesn't download sources when building locally - url

Question

I'm trying to add some patches to the llvm Opam package, but I'm having issues testing it because it seems like running opam install . from the package root ignores the url section and doesn't download & decompress the source archive, thus failing when applying patches.
This is the opam file for reference:
opam-version: "2.0"
maintainer: "Kate <kit.ty.kate#disroot.org>"
authors: [
"whitequark <whitequark#whitequark.org>"
"The LLVM team"
]
license: "MIT"
doc: "http://llvm.moe/ocaml"
bug-reports: "http://llvm.org/bugs/"
dev-repo: "git+http://llvm.org/git/llvm.git"
homepage: "http://llvm.moe"
install: [
["bash" "-ex" "install.sh" "%{conf-llvm:config}%" lib "%{conf-cmake:cmd}%" make]
]
depends: [
"ocaml" {>= "4.00.0"}
"ctypes" {>= "0.4"}
"ounit" {with-test}
"ocamlfind" {build}
"conf-llvm" {build & = version}
"conf-python-2-7" {build}
"conf-cmake" {build}
]
patches: [
"fix-shared.patch"
]
synopsis: "The OCaml bindings distributed with LLVM"
description: "Note: LLVM should be installed first."
extra-files: [
["link-META.patch" "md5=ef4ebb8706be2ed402f31fc351d7dc75"]
["install.sh" "md5=683ec0478ee422a57dcd3716277b3ef3"]
["fix-shared.patch" "md5=dce86b1db352332968ceb6d042b408a8"]
["META.patch" "md5=1d0af08bab7a0f831f68849b6556e414"]
["add-buildfence-llvm.ml.patch" "md5=a3bc667bd2fc937ee51c3b9d33b8ad63"]
["add-buildfence-llvm.mli.patch" "md5=99c739d74deeb1b990fe63cf914fc479"]
["add-buildfence-llvm_ocaml.c.patch" "md5=a29282f2e1e435abff57cecfd269ccb9"]
]
url {
src: "https://github.com/llvm/llvm-project/releases/download/llvmorg-11.1.0/llvm-11.1.0.src.tar.xz"
checksum: "sha256=ce8508e318a01a63d4e8b3090ab2ded3c598a50258cc49e2625b9120d4c03ea5"
}
and this is the result of running opam install . -vvv on the package root:
Processing 1/1: [llvm.11.0.0: rsync]
+ /usr/bin/rsync "-rLptgoDrvc" "--exclude" ".git" "--exclude" "_darcs" "--exclude" ".hg" "--exclude" ".#*" "--exclude" "_opam*" "--delete" "--delete-excluded" "/home/frabert/opam-repository/packages/llvm/llvm.11.0.0/" "/home/frabert/.opam/4.11.1/.opam-switch/sources/llvm"
- sending incremental file list
- ./
- out
-
- sent 828 bytes received 39 bytes 1,734.00 bytes/sec
- total size is 19,120 speedup is 22.05
[llvm.11.0.0] synchronised from file:///home/frabert/opam-repository/packages/llvm/llvm.11.0.0
+ /usr/bin/lsb_release "-s" "-r"
- 18.04
+ /usr/bin/ocamlc "-vnum"
- 4.05.0
The following actions will be performed:
∗ install llvm 11.0.0*
+ /usr/bin/rsync "-rLptgoDrvc" "--exclude" ".git" "--exclude" "_darcs" "--exclude" ".hg" "--exclude" ".#*" "--exclude" "_opam*" "--delete" "--delete-excluded" "/home/frabert/opam-repository/packages/llvm/llvm.11.0.0/" "/home/frabert/.opam/4.11.1/.opam-switch/sources/llvm"
- sending incremental file list
- ./
- opam
- out
- files/
- files/META.patch
- files/add-buildfence-llvm.ml.patch
- files/add-buildfence-llvm.mli.patch
- files/add-buildfence-llvm_ocaml.c.patch
- files/fix-shared.patch
- files/install.sh
- files/link-META.patch
-
- sent 20,648 bytes received 202 bytes 41,700.00 bytes/sec
- total size is 19,775 speedup is 0.95
[llvm.11.0.0] synchronised from file:///home/frabert/opam-repository/packages/llvm/llvm.11.0.0
<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
+ /bin/cp "-PRp" "/home/frabert/.opam/4.11.1/.opam-switch/sources/llvm" "/home/frabert/.opam/4.11.1/.opam-switch/build/llvm.11.0.0"
+ /bin/cp "/home/frabert/.opam/4.11.1/.opam-switch/overlay/llvm/files/link-META.patch" "/home/frabert/.opam/4.11.1/.opam-switch/build/llvm.11.0.0/link-META.patch"
+ /bin/cp "/home/frabert/.opam/4.11.1/.opam-switch/overlay/llvm/files/install.sh" "/home/frabert/.opam/4.11.1/.opam-switch/build/llvm.11.0.0/install.sh"
+ /bin/cp "/home/frabert/.opam/4.11.1/.opam-switch/overlay/llvm/files/fix-shared.patch" "/home/frabert/.opam/4.11.1/.opam-switch/build/llvm.11.0.0/fix-shared.patch"
+ /bin/cp "/home/frabert/.opam/4.11.1/.opam-switch/overlay/llvm/files/add-buildfence-llvm_ocaml.c.patch" "/home/frabert/.opam/4.11.1/.opam-switch/build/llvm.11.0.0/add-buildfence-llvm_ocaml.c.patch"
+ /bin/cp "/home/frabert/.opam/4.11.1/.opam-switch/overlay/llvm/files/add-buildfence-llvm.mli.patch" "/home/frabert/.opam/4.11.1/.opam-switch/build/llvm.11.0.0/add-buildfence-llvm.mli.patch"
+ /bin/cp "/home/frabert/.opam/4.11.1/.opam-switch/overlay/llvm/files/add-buildfence-llvm.ml.patch" "/home/frabert/.opam/4.11.1/.opam-switch/build/llvm.11.0.0/add-buildfence-llvm.ml.patch"
+ /bin/cp "/home/frabert/.opam/4.11.1/.opam-switch/overlay/llvm/files/META.patch" "/home/frabert/.opam/4.11.1/.opam-switch/build/llvm.11.0.0/META.patch"
+ /bin/cp "/home/frabert/.opam/4.11.1/.opam-switch/build/llvm.11.0.0/fix-shared.patch" "/home/frabert/.opam/log/processed-patch-13793-c743ac"
Processing 1/2: [llvm: patch]
+ /usr/bin/patch "-p1" "-i" "/home/frabert/.opam/log/processed-patch-13793-c743ac" (CWD=/home/frabert/.opam/4.11.1/.opam-switch/build/llvm.11.0.0)
- can't find file to patch at input line 5
- Perhaps you used the wrong -p or --strip option?
- The text leading up to this was:
- --------------------------
- |diff --git a/cmake/modules/AddOCaml.cmake b/cmake/modules/AddOCaml.cmake
- |index 554046b20..b27cbd36c 100644
- |--- a/cmake/modules/AddOCaml.cmake
- |+++ b/cmake/modules/AddOCaml.cmake
- --------------------------
- File to patch:
- Skip this patch? [y]
- Skipping patch.
- 1 out of 1 hunk ignored
<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
┌─ The following actions failed
│ λ build llvm 11.0.0
└─
╶─ No changes have been performed
Is this a known problem?
EDIT: Clarification regarding the workflow
I have a local git clone of the opam-repository, of which I have edited and committed the llvm.11.0.0 package definition.
To test the edits, I run opam install . from inside the llvm.11.0.0 directory which contains the opam file.

Answer 1

The correct1 workflow for changing a package definition in the ocaml/opam-repository is the following.
clone the opam-repository
git clone git#github.com:ocaml/opam-repository.git
add the local repository to the opam repo list
opam repo add local ./opam-repository
make a copy of the package that you would like to change (using llvm as the working example), we will use -<patch> since we're just adding a patch, not releasing a new version,
cd opam-repository/packages/llvm/
cp -r llvm.11.0.0/ llvm.11.0.0-1
work with the patched version ...
commit the work
git add llvm.11.0.0-1
git commit -m 'wip'
test it
opam update
opam install llvm
1) Well, at least it is the workflow that I am using everyday :)

Answer 2

I was using the wrong workflow, as hinted correctly by #ivg
The correct one, though, appears to be the one described here: https://github.com/ocaml/opam/issues/4654
Basically, I needed to add a local repository, and then install the llvm package as usual.
opam repo add local ~/opam-repository
opam install llvm