If the line with replacement cannot be constructed xargs should terminate as
documented in the man page:
-I replstr Execute utility for each input line, replacing one or more occurrences of replstr in up to replacements (or 5 if no -R flag is specified) arguments to utility with the entire line of input. The resulting arguments, after replacement is done, will not be allowed to grow beyond replsize (or 255 if no -S flag is specified) bytes; this is implemented by concatenating as much of the argument containing replstr as possible, to the constructed arguments to utility, up to replsize bytes. The size limit does not apply to arguments to utility which do not contain replstr, and furthermore, no replacement will be done on utility itself. Implies -x.
Currently, xargs continues and lines that cannot accommodate the replacement get
as much of the replstr as will fit in the string. Instead xargs should error,
include an error when we do.
We encounter this error, but gnu/xargs doesn't because they have a much larger
limit for created outputs (~10000 lines).