I'm trying to build a package on a private OBS server for CentOS_7. (I've built it successfully for openSUSE 42.2-15.4.) This package build has a _service file that contains

<service name="set_version" mode="buildtime"/>

I have linked obs-service-set_version into my project, and enabled it for CentOS_7. The build seems to succeed. In fact, when I inspect the build log for my package, I'm seeing:

[ 13s] processing recipe /.build-srcdir/_service:tar_scm:rslib.spec ...

[ 13s] init_buildsystem --configdir /.build/configs --cachedir /var/cache/build /.build-srcdir/_service:tar_scm:rslib.spec build ...

[ 13s] initializing rpm db...

[ 13s] querying package ids...

[ 14s] [1/362] installing adobe-mappings-cmap-20171205-3.el7

(other intervening packages...)

[ 16s] [10/362] installing obs-service-set_version-0.5.14-1.1

But then, at the end, I'm seeing

[ 81s] Running build time source services...

[ 81s] Can't exec "/usr/lib/obs/service/set_version": No such file or directory at /.build/runservices line 87.

[ 81s] /usr/lib/obs/service/set_version: No such file or directory

[ 81s] service run failed for service 'set_version'

The build stops after that. I've checked the RPM created for obs-service-set_version (obs-service-set_version-0.5.14-1.1.noarch.rpm) and it does contain "/usr/lib/obs/service/set_version", so I'm a bit puzzled now. Could anybody give me a hint?