I'm in the process of upgrading a set of bird instances from v1 to v2. The running configurations of these nodes were written circa ten years ago, for a network that since has shrunk quite a lot, nethertheless I would like to change them as little as possible. During preparation work I've hit a snag: most of these configurations use routes scope as one of the filtering criterions but bird v2 experience some grammatical difficulties when parsing them. The user manual states that one can access and mutate a route scope through the "scope" symbol (section 5.5). Nonetheless, the configuration file parser rejects the following two functions---these are fictious functions written to concisely replicate the problem, they are accompanied by the error message produced by "bird -c <file> -p". function ScopeAccess () -> bool { return scope = SCOPE_HOST; } bird: 2025-11-26 10:30:02.631 [0001] <FATAL> scope-access.conf:3:10 syntax error, unexpected SCOPE function ScopeSet () -> bool { scope = SCOPE_HOST; return true; } bird: 2025-11-26 10:31:25.081 [0001] <FATAL> scope-set.conf:3:3 syntax error, unexpected SCOPE I had a quick look into "config.Y". I can't predend I fully understand how the grammar is constructed due to a cursory glance, however I suppose the constructions shown above are covered by the "term: ... static_attr ..." and "cmd: ... symbol_known '=' term ';'" productions. When using the manual and these productions as supporting material I think the two functions shown above are legit. Am I correct? Then I looked at "test.conf" where I found a construction involving "scope" used not as an attribute but as a type, a declaration that is not part of the documentation: "enum scope ev2 = SCOPE_UNIVERSE;". This construction, accepted by the parser, is contradicting the user manual. Quoting it, section 5.2: "Enumeration types are fixed sets of possibilities. You can't define your own variables of such type, but some route attributes are of enumeration type." With regard to this undocumented declarative form, at this stage, I'm wondering if a grammatical ambiguity could exist between "scope" the type and "scope" the attribute? -- %!PS -- Bertrand Petit /D{def}def/E{exch}D/G{get}D/I{2 div}D/U{dup}D/L{roll}D/Y{setgray}D/N{newpath}D /O{N 0 0 moveto}D/P{pop}D/T{translate}D currentpagedevice/PageSize G U 0 G/w E D 1 G /h E D w I h I T 0 Y 1 setlinewidth 0 1 2 { P 120 rotate 2 4 w U mul h U mul add sqrt I 50 add {N 50 0 3 2 L 0 360 arc stroke}for}for/s{O true charpath pathbbox exch 4 -1 L E sub I 3 1 L sub I} D /l(bp)D 0.94 Y /Helvetica findfont 22 scalefont setfont l s P(x)s exch P T O l show showpage