At the end of making curl:
'i686-pc-mingw32-gcc' -W -Wall -Werror -ansi -pedantic
'./src/curl-test.c' -o
'/opt/mxe/usr/i686-pc-mingw32/bin/test-curl.exe'
`'i686-pc-mingw32-pkg-config' libcurl --cflags --libs`
i686-pc-mingw32-gcc: @CPPFLAG_CURL_STATICLIB@: No such file or directory
make[1]: *** [build-only-curl] Error 1
The output of pkg-config causes the problem:
$ i686-pc-mingw32-pkg-config libcurl --cflags --libs
@CPPFLAG_CURL_STATICLIB@ -I/opt/mxe/usr/i686-pc-mingw32/include
-L/opt/mxe/usr/i686-pc-mingw32/lib -lcurl -lcares -lidn -lintl -liconv
-lwldap32 -lssh2 -lssl -lcrypto -lgdi32 -lcrypt32 -lz -lws2_32
Which of course is an error in
usr/i686-pc-mingw32/lib/pkgconfig/libcurl.pc, the last line :
Cflags: -I${includedir} @CPPFLAG_CURL_STATICLIB@
which comes from src/curl-1-fixes.patch, line 106:
+Cflags: -I${includedir} @CPPFLAG_CURL_STATICLIB@
The variable never gets substituted.