# Linux release binaries: RUNPATH for /opt/moonbite/lib

The MoonBite seed nodes run Ubuntu 24.04 but the Linux `moonbited` /
`moonbite-cli` binaries are built natively on Ubuntu 22.04 against the 22.04
system libraries (libboost 1.74, libevent, libdb5.3, libzmq, libfmt8, ...).
Those exact `.so` versions are not in the 24.04 archive, so the seeds carry a
copy of them in `/opt/moonbite/lib` (shipped once with `ship_libs.sh`).

For the dynamic loader to find them the binaries must carry a RUNPATH that
points at that directory. Binaries built without it fail with
`libboost_filesystem.so.1.74.0: not found` on the seeds and had to be fixed
on-host with `patchelf --set-rpath /opt/moonbite/lib` (regression seen with
the 981ca8669 build, 2026-10-09).

**Every native Linux build intended for the seeds must therefore be configured
with:**

```sh
./configure --prefix=/ --disable-tests --disable-bench --with-incompatible-bdb \
    CPPFLAGS=-DBOOST_NO_CXX98_FUNCTION_BASE \
    LDFLAGS="-Wl,-rpath,/opt/moonbite/lib"
```

and verified before staging:

```sh
readelf -d src/litecoind    | grep -i runpath   # -> Library runpath: [/opt/moonbite/lib]
readelf -d src/litecoin-cli | grep -i runpath
```

Notes:

- The RUNPATH is only *searched*; it does not break hosts that have the libs in
  the normal system paths (the loader falls through to `/usr/lib/...`), so the
  same binary still runs on a plain 22.04 box or in WSL.
- The GitHub Actions `release.yml` builds with the `depends` system (static
  boost/libevent/zmq), so RUNPATH is not strictly needed there; it is still set
  on the Linux matrix entry so the public tarball and the seed-staged build are
  linked identically and `patchelf` is never required on-host again.
- `deploy/deploy-droplet-node.sh` in moonbite-network still contains the
  `patchelf` fallback as a safety net, but a correctly built binary never hits it.