(.fea merge) unparseable glyph sequence

[tayloraswift]

Any reason why fontforge doesn’t like lines 12 and 27 of
(sub \startsc @sccharacters by @scflags;) and (sub @scflags \less \slash s c \greater by @scbase;)? Or am I breaking some .fea rule?

@sccharacters = [\a \b \c \d \e \f \g \h \i \j \k \l \m \n \o \p \q \r \s \t \u \v \w \x \y \z ];

@scbase = [\a.smcp \b.smcp \c.smcp \d.smcp \e.smcp \f.smcp \g.smcp \h.smcp \i.smcp \j.smcp \k.smcp \l.smcp \m.smcp \n.smcp \o.smcp \p.smcp \q.smcp \r.smcp \s.smcp \t.smcp \u.smcp \v.smcp \w.smcp \x.smcp \y.smcp \z.smcp ];

@scflags = [\a.smcpflag \b.smcpflag \c.smcpflag \d.smcpflag \e.smcpflag \f.smcpflag \g.smcpflag \h.smcpflag \i.smcpflag \j.smcpflag \k.smcpflag \l.smcpflag \m.smcpflag \n.smcpflag \o.smcpflag \p.smcpflag \q.smcpflag \r.smcpflag \s.smcpflag \t.smcpflag \u.smcpflag \v.smcpflag \w.smcpflag \x.smcpflag \y.smcpflag \z.smcpflag ];

feature liga {
lookup SmallCapsOpen {
sub \less s c \greater by \startsc;
} SmallCapsOpen;
lookup SmallCapsInitialize {
sub \startsc @sccharacters by @scflags;
} SmallCapsInitialize;
} liga;

feature calt {
lookup SmallCapsChaining {
sub @scflags @sccharacters' by @scflags;
} SmallCapsChaining;
lookup SmallCapsRendering {
sub @scflags' @scflags by @scbase;
} SmallCapsRendering;
} calt;

feature liga {
lookup SmallCapsInitialize {
sub @scflags \less \slash s c \greater by @scbase;
} SmallCapsInitialize;
} liga;

[adrientetar]

What's this small caps initialize stuff? As I use small caps it's just a one-to-one substitution.

[tayloraswift]

It’s a font-side system for imputting small capitals in programs that don’t let you select opentype features

[adrientetar]

If you want to see what's wrong I'd say try to compile the fea with makeotf. Pass it a UFO along with the fea file using the -ff switch.