Changes in ocaml-ppxlib 0.23.0:

• Drop Parser from the API (#263, @pitag-ha)

• Location: add set_filename and Error.get_location (#247, @pitag-ha)

• Drop dependency on OMP2 (#187, @pitag-ha)

• Make OMP1 a conflict (#255, @kit-ty-kate)

• Drop Syntaxerr from the public API. Doesn't affect any user in the ppx universe (#244, @pitag-ha)

• Add a lower-bound constraint for Sexplib0 (#240, @pitag-ha)

• Fix bug due to which unwanted public binaries got installed when installing ppxlib (#223, @pitag-ha)

• Add Keyword.is_keyword to check if a string is an OCaml keyword (#227, @pitag-ha)

• Remove Lexer.keyword_table: use Keyword.is_keyword instead (#227, @pitag-ha)

• Remove Lexer from the API: it was the same as the compiler-libs Lexer (#228, @pitag-ha)

• Remove the modules Ast_magic, Compiler_version, Js, Find_version, Convert, Extra_warnings, Location_error, Select_ast and Import_for_core from the API: they are meant for internal use and aren't used by any current downstream user in the ppx universe (#230, @pitag-ha)

• Remove compiler specific helper functions from Location. They aren't used by any current downstream user in the ppx universe (#238, @pitag-ha)

• Allow "%a" when using Location.Error.createf (#239, @mlasson)

• Fix in Location: make raise_errorf exception equivalent to exception Error (#242, @pitag-ha)

• Fix in Pprintast: correctly pretty print local type substitutions, e.g. type t := ... (#261, @matthewelse)

• Add Ast_pattern.esequence, for matching on any number of sequenced expressions e.g. do_a (); do_b (); .... (#264, @matthewelse)

• Expose a part of Ast_io in order to allow reading AST values from binary files (#270, @arozovyk)

Changes in ocaml-sedlex 2.4:

• Update dune support to 2.8, add auto-generated opam files.
• Optimize generated code, thanks to @bobzhang
• Update unicode version to 13.0.0

All other builds are simple rebuilds due to the ocaml-ppxlib update.