Are circular dependencies problematic?

[Richard Hansen <rhansen@rhansen.org>]

Hi all,

Is it a problem to have a Depends cycle among the golang-*-dev packages?

golang.org/x/net and golang.org/x/crypto require each other in their 
go.mod files, but I noticed that the golang-golang-x-crypto-dev Debian 
package contains a copy of the golang.org/x/net/idna Go package to break 
that dependency cycle: 
<https://salsa.debian.org/go-team/packages/golang-go.crypto/-/blob/debian/latest/debian/README.source>.

I thought dpkg could handle circular dependencies.  Would a cycle cause 
FTBFS?  Can an older version of the package being built be installed to 
satisfy the circular dependency while building the newer version of the 
package?

Thanks,
Richard