toAbsolutePath filename
i1 : toAbsolutePath "a/b.m2" o1 = /home/m2user/src/M2.git/M2/BUILD/dan/builds.tmp/ub22041-release-1.21-branch /Macaulay2/packages/Macaulay2Doc-temporary/a/b.m2
Paths of the form foo/x/../bar, are shortened to foo/bar without checking the file system to see whether x is a symbolic link. For the other behavior, see realpath.
The object toAbsolutePath is a function closure.