makerepropkg: use correct devtools makepkg.conf files from dist

Use the recorded buildtool in order to download the matching dist
package and use the appropriate makepkg.conf for reproducing the
package. This is required as the flags are not recorded in the BUILDINFO
hence we need to provide the matching config that declared those flags.

1 files changed, 11 insertions, 0 deletions

diff --git a/README.md b/README.md
index 0f5d8f2..c4bc8f4 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,17 @@ as following.
 git config format.subjectprefix 'devtools] [PATCH'
 ```
 
+## Building
+
+When building official distro packages the `BUILDTOOLVER` needs to be set to the
+exact label of the release package in order to allow to detect the exactly used
+devtools version. This is required for reproducible builds to fetch the according
+files like `makepkg.conf`.
+
+```sh
+BUILDTOOLVER="${pkgver}-${pkgrel}-${arch}" make all
+```
+
 ## Releasing
 
 1. bump the version in the Makefile