XO1320: `xo mod tidy` cannot record a pinned Go module's hashes yet

xo.lock records the go.sum hashes of every pinned Go module from the binding workspace (.xo/gobind/_mod, or $XO_GOBIND_DIR), which xo check, build, run and test create when they bind the package with Go. In a fresh clone the workspace does not exist (it is not committed), so tidy has nothing to copy; rather than write an xo.lock without the module’s lines and succeed, it stops. Run xo check once, then xo mod tidy again. See decision 0356.

Example

# a fresh clone: xo.mod has the pin, no .xo/ yet
require go github.com/google/uuid v1.6.0

Fix

xo check .
xo mod tidy

Run xo explain XO1320 for this text in a terminal, or see section 10.6 of the specification.