$(info text…) and missing endif

Hi Everyone,

I'm testing a makefile on Ubuntu 4 with GNU Make 3.80. The makefile is
failing with:

    $ make -j 3
    GNUmakefile:1857: *** missing `endif'.  Stop.

The problem area seems to be
(https://github.com/weidai11/cryptopp/blob/master/GNUmakefile#L1821):

ifeq ($(IS_DARWIN)$(CLANG_COMPILER),11)
  ifeq ($(findstring -stdlib=libc++,$(CRYPTOPP_CXXFLAGS)$(CXXFLAGS)),)
    $(info )
    $(info INFO: Crypto++ was built without LLVM's libc++. If you are
using the library)
    $(info INFO: with modern Xcode, then you should add -stdlib=libc++
to CXXFLAGS. It is)
    $(info INFO: already present in the makefile, and you only need to
uncomment it.)
    $(info )
  endif
endif

In my text editor (Kate), the two closing endif's are colored
differently, like they are not part of reserved words. I checked
https://www.gnu.org/software/make/manual/make.html#Make-Control-Functions
, but I don't see what is wrong with the text.

Trial and error, by commenting out this line, the structure is restored in Kate:

    #$(info INFO: Crypto++ was built without LLVM's libc++. If you are
using the library)

What is wrong with the use of $(info text…) in this case?

Thanks in advance.