/usr/lib/R/site-library/rncl/nexusfiles/ is in r-cran-rncl 0.8.2-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/R/site-library/rncl/nexusfiles/MultiLineTrees.nex
/usr/lib/R/site-library/rncl/nexusfiles/badnex.nex
/usr/lib/R/site-library/rncl/nexusfiles/co1.nex
/usr/lib/R/site-library/rncl/nexusfiles/multiLines.rds
/usr/lib/R/site-library/rncl/nexusfiles/newick.tre
/usr/lib/R/site-library/rncl/nexusfiles/test_empty.nex
/usr/lib/R/site-library/rncl/nexusfiles/test_subset_alltaxa.nex
/usr/lib/R/site-library/rncl/nexusfiles/test_subset_taxa.nex
/usr/lib/R/site-library/rncl/nexusfiles/test_underscores.nex
/usr/lib/R/site-library/rncl/nexusfiles/treeWithDiscreteData.nex
/usr/lib/R/site-library/rncl/nexusfiles/treeWithUnderscoreLabels.nex