kicad-developers team mailing list archive

[Julius Schmidt <aiju@xxxxxxxxxx>]

On Wed, 22 Nov 2017, Wayne Stambaugh wrote:

> First of all, you cannot opt out of remapping you schematic and expect
> the library symbol links to continue to work correctly.  The symbol
> library table is now the only way that library symbols are linked to
> schematics symbols.  The only reason any of your symbols show up is that
> they are still in the cache library.

I see. So I cannot look at old schematics files without converting them
to the new format. I understand the technical reasons but the act of
opening modifying a file on-disk that breaks it for older versions
is not something I'd ever expect a program to do.

So basically to look at older files I should keep an older version of 
kicad around ...

> This change is not just for the upcoming file format changes, it also
> fixes a major bug that caused the wrong symbol to be linked in certain
> situations and has been in the project forever.

Do you have an example at hand?

> No it didn't.  You were just lucky.  IMO, the symbol cache library has
> always been a disaster waiting to happen and it masked a lot of issues
> with broken and modified symbol libraries.  Your desire to have a single
> symbol footprint link is not shared by all.  Many users like the idea of
> being able modify symbols in place like you can with footprints.  There
> are many times I would like to tweak pin positions in symbols to make
> schematics cleaner without having to have multiple variants of the same
> symbol in my libraries.

I understand the desire to have modified versions of symbols, but it
also seems to make centralised updates of symbols impossible, at least
not without losing these changes, which in the case of swapped pins
could be rather disastrous. (Yes, with the multiple copies approach you
have to edit each copy individually, but at least it's explicit what's
going on). Though I guess you could keep the old version and check if it 
was locally modified before replacing.

I know this may be just personal preference, but when a wrong change
could cost me a lot of money I'd much prefer my software to be as
explicit about them as possible.

Sorry, really not trying to impose my views on anyone, just curious
about the mindset behind these things.