  Consider a vertex-weighted graph $G$ with a source $s$ and a target $t$.
Tracking Paths requires finding a minimum weight set of vertices (trackers)
such that the sequence of trackers in each path from $s$ to $t$ is unique. In
this work, we derive a factor $6$-approximation algorithm for Tracking Paths in
weighted graphs and a factor $4$-approximation algorithm if the input is
unweighted. This is the first constant factor approximation for this problem.
While doing so, we also study approximation of the closely related $r$-Fault
Tolerant Feedback Vertex Set problem. There, for a fixed integer $r$ and a
given vertex-weighted graph $G$, the task is to find a minimum weight set of
vertices intersecting every cycle of $G$ in at least $r+1$ vertices. We give a
factor $\mathcal{O}(r)$ approximation algorithm for $r$-Fault Tolerant Feedback
Vertex Set if $r$ is a constant.
