File ‘lidR/libs/lidR.so’:
  Found non-API calls to R: ‘LEVELS’, ‘R_curErrorBuf’, ‘SETLENGTH’,
    ‘SET_GROWABLE_BIT’, ‘SET_TRUELENGTH’, ‘TRUELENGTH’, ‘XTRUELENGTH’

Compiled code should not call non-API entry points in R.

See ‘Writing portable packages’ in the ‘Writing R Extensions’ manual,
and section ‘Moving into C API compliance’ for issues with the use of
non-API entry points.
File ‘lidR/libs/lidR.so’:
  Found non-API calls to R: ‘LEVELS’, ‘R_curErrorBuf’, ‘SETLENGTH’,
    ‘SET_GROWABLE_BIT’, ‘SET_TRUELENGTH’, ‘TRUELENGTH’, ‘XTRUELENGTH’

Compiled code should not call non-API entry points in R.

See ‘Writing portable packages’ in the ‘Writing R Extensions’ manual,
and section ‘Moving into C API compliance’ for issues with the use of
non-API entry points.
File 'lidR/libs/x64/lidR.dll':
  Found non-API calls to R: 'LEVELS', 'R_curErrorBuf', 'SETLENGTH',
    'SET_GROWABLE_BIT', 'SET_TRUELENGTH', 'TRUELENGTH', 'XTRUELENGTH'

Compiled code should not call non-API entry points in R.

See 'Writing portable packages' in the 'Writing R Extensions' manual,
and section 'Moving into C API compliance' for issues with the use of
non-API entry points.