%define tde_pkg abakus
Name: trinity-%{tde_pkg}
Package name is "trinity-abakus"
and,
yum install trinity-abakus
would be the correct command to install the abakus package?
Yes, both are correct.
FYI, it is possible to define macros(*) in terms of other macros, something
like this:
%define tde_a a
%define tde_pkg %{a}b%{a}kus
Name: trinity-%tde_pkg
Still giving package name "trinity-abakus"
So, ideally, resolving definitions should be recursive.
The curly braces are only necessary if there's other text immediately
following (similar to the rules for $name vs ${name} in bash shell scripting).
This is the most compact link I could find for RPM syntax:
https://rpm-packaging-guide.github.io/#what-is-a-spec-file
_____
(*) In proper RPM terminology, what we humans would think of as a "variable"
is considered a really simple "macro" definition. Any substitutable thing is
called a "macro", even a simple string substitution like the two defined in
the example.
Douglas