Describe the issue

If I run ./configure without the utfcpp dependency available, it completes successfully, even though make will fail.

Can you reliably reproduce the issue?

Yes.

If so, please list the steps to reproduce below:

I haven't made a reproduction from a standard zcash branch yet. That approach might be to checkout v4.0.0, then somehow remove utfcpp completely from ./depends tracking so that it won't be rebuilt, then run ./zcutil/build.sh.

This is the quick'n'dirty way that requires having nix installed:

1. git clone 'https://github.com/nathan-at-least/zcash'
2. cd ./zcash
3. git checkout 745435147 # see nathan-at-least@7454351
4. nix-build ./zcutil/nix-builder/zcash

Notice that the next commit in that branch (https://github.com/nathan-at-least/zcash/commits/nix-builder.3.WIP) is described as "Port utfcpp from depends to nix" (see nathan-at-least@e3ff555 ). That branch will successfully get past this make failure because it puts utfcpp headers in the right place.

It does not fix the bug for this ticket though, because it doesn't alter the config system (./configure.ac).

Expected behaviour

./configure should exit complaining that it cannot detect the utfcpp dependency.

Actual behaviour + errors

make fails with:

wallet/rpcwallet.cpp:40:10: fatal error: utf8.h: No such file or directory
   40 | #include <utf8.h>

The version of Zcash you were using:

Based off of v4.0.0.