portupgrade -ar (why?)
Jan Grant
Jan.Grant at bristol.ac.uk
Sat Oct 15 11:32:40 PDT 2005
On Sat, 15 Oct 2005, Peter Matulis wrote:
> What is the use of specifying the 'r' switch when using the 'a'
> switch?
>
> # portupgrade -ar
>
> This says to upgrade all ports plus the ones that depend on all
> those ports. Am I missing something? Wouldn't "the ones that
> depend" be upgraded anyway?
Not necessarily. For instance: package P might use library L. A change
in L might alter the size and layout of structures exposed to P. The
source-level API of L is unchanged; the binary-level ABI is altered. So
whilst the source code of P might not have changed, it might (for
instance) be using a macro defined by a header in L that will look at
the wrong offset in the new structure. These kinds of ABI compatibility
problems can be fixed by recompilihng P.
--
jan grant, ILRT, University of Bristol. http://www.ilrt.bris.ac.uk/
Tel +44 (0)117 3317661 http://ioctl.org/jan/
Strive to live every day as though it was last Wednesday.
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