Postcss8 loader error on svg core styles.css

[K-zimm]

Running in nuxt with postcss8.

It is having trouble with one particular line. When I commend it out build completes fine and app works great. Seems that it doesn't like the calc() function on line 202 of styles.css in fontawesome-svg-core The parser cries about the -1.

[robmadole]

@K-zimm can you provide a reproducible test case for this?

[tobiasdiez]

I got the same issue while upgrading fontawesome-svg-core from 1.2.36 to 1.3.0 JabRef/JabRefOnline#837.
As @K-zimm says, the problem is in the line for left:

.fa-li {
  left: calc(var(--fa-li-width, 2em) * -1);
  position: absolute;
  text-align: center;
  width: var(--fa-li-width, 2em);
  line-height: inherit; }

[JSAustin]

I also get the same issue. Having a lot of trouble getting past this.

[robmadole]

That's syntactically correct as far as I know (multiplying by -1). Have you reached out to the postcss folks on this?

[jsayer101]

@K-zimm Hi ! We've got the same error here, how did you solved this issue ? We got no clue how to fix this.

[tobiasdiez]

I did a bit of digging and it seems like postcss-values-parser has/had troubles with the multiplication operator in combination with -1, see eg shellscape/postcss-values-parser#126 and shellscape/postcss-values-parser#138. As the latter issue is already closed, one solution might be to upgrade postcss-values-parser.

I guess usually postcss-values-parser is invoked by postcss-custom-properties. More recent version of postcss-custom-properties however directly use postcss-value-parser (without s) instead of ``postcss-values-parser(with s). Thus upgradingpostcss-custom-properties` should fix this issue as well. However, some frameworks like nuxt still use a rather old version of these postcss plugins (there is the stalled nuxt/nuxt#10060 to upgrade these).

[tobiasdiez]

That being said, what worked for me was to replace the offending line in styles.css with

left: calc(-1 * var(--fa-li-width, 2em));

(i.e. move the minus 1 multiplication to the front).

[robmadole]

I'm going to close this as it's not a bug with this library.