Clang-10 prints many warnings, some look damaging

[yurivict]

/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/checksum.c:240:39: warning: comparison of integers of different signs: 'ssize_t' (aka 'long') and 'size_t' (aka 'unsigned long') [-Wsign-compare]
                *matches = (attr_size == expected_len || attr_size == expected_len + 1) &&
                            ~~~~~~~~~ ^  ~~~~~~~~~~~~
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/checksum.c:240:68: warning: comparison of integers of different signs: 'ssize_t' (aka 'long') and 'unsigned long' [-Wsign-compare]
                *matches = (attr_size == expected_len || attr_size == expected_len + 1) &&
                                                         ~~~~~~~~~ ^  ~~~~~~~~~~~~~~~~
2 warnings generated.
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/downloader.c:747:41: warning: comparison of integers of different signs: 'unsigned int' and 'int' [-Wsign-compare]
            } else if (mirrors_iterated < c_mirror->failed_transfers) {
                       ~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/url_substitution.c:132:33: warning: comparison of integers of different signs: 'size_t' (aka 'unsigned long') and 'long' [-Wsign-compare]
                    if (var_len == cur - varname && strncmp(var_val->var, varname, var_len) == 0) {
                        ~~~~~~~ ^  ~~~~~~~~~~~~~
1 warning generated.
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/yum.c:444:42: warning: unused parameter 'fd' [-Wunused-parameter]
                                     int fd,
                                         ^
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/yum.c:797:13: warning: variable 'fd' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
        if (is_zchunk) {
            ^~~~~~~~~
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/yum.c:821:40: note: uninitialized use occurs here
                                       fd,
                                       ^~
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/yum.c:797:9: note: remove the 'if' if its condition is always false
        if (is_zchunk) {
        ^~~~~~~~~~~~~~~~
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/yum.c:755:15: note: initialize the variable 'fd' to silence this warning
        int fd;
              ^
               = 0
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/yum.c:1033:9: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
    if (is_zchunk) {
        ^~~~~~~~~
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/yum.c:1062:12: note: uninitialized use occurs here
    assert(ret || tmp_err);
           ^~~
/usr/include/assert.h:56:21: note: expanded from macro 'assert'
#define assert(e)       ((e) ? (void)0 : __assert(__func__, __FILE__, \
                          ^
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/yum.c:1033:5: note: remove the 'if' if its condition is always false
    if (is_zchunk) {
    ^~~~~~~~~~~~~~~~
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/yum.c:987:17: note: initialize the variable 'ret' to silence this warning
    gboolean ret, matches;
                ^
                 = 0
3 warnings generated.
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/python/handle-py.c:1189:12: warning: missing field 'ml_meth' initializer [-Wmissing-field-initializers]
    { NULL }
           ^
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/python/handle-py.c:1233:1: warning: missing field 'tp_bases' initializer [-Wmissing-field-initializers]
};
^
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/python/metadatatarget-py.c:429:12: warning: missing field 'ml_meth' initializer [-Wmissing-field-initializers]
    { NULL }
           ^
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/python/metadatatarget-py.c:473:1: warning: missing field 'tp_bases' initializer [-Wmissing-field-initializers]
};
^
2 warnings generated.
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/python/result-py.c:211:12: warning: missing field 'ml_meth' initializer [-Wmissing-field-initializers]
    { NULL }
           ^
/usr/ports/misc/librepo/work/librepo-1.12.1/librepo/python/result-py.c:255:1: warning: missing field 'tp_bases' initializer [-Wmissing-field-initializers]
};
^
2 warnings generated.