尝试在Win 10下升级我的Portable Msys2时遇到问题，详情如下。我以前这样做没有问题。pacman -Syuu
问题和解决方案可能是什么？
$ pacman -Syuu
:: Synchronizing package databases...
mingw32 is up to date
mingw64 is up to date
msys is up to date
:: Starting core system upgrade...
there is nothing to do
:: Starting full system upgrade...
warning: grep: downgrading from version 3.1-1 to version 3.0-2
warning: libgc: downgrading from version 8.0.0-1 to version 7.6.8-1
warning: mingw-w64-x86_64-binutils: downgrading from version 2.31.1-2 to version 2.30-5
:: Replace mingw-w64-x86_64-minizip with mingw64/mingw-w64-x86_64-zlib? [Y/n] y
:: Replace mingw-w64-x86_64-vulkan with mingw64/mingw-w64-x86_64-vulkan-loader? [Y/n] y
resolving dependencies...
looking for conflicting packages...
Packages (217) autogen-5.18.16-1 bison-3.3.2-1 brotli-1.0.7-1 ca-certificates-20180409-1 cmake-3.13.2-1 curl-7.64.0-2 diffutils-3.7-1 doxygen-1.8.15-1
...
Total Download Size: 1400.65 MiB
Total Installed Size: 9648.15 MiB
Net Upgrade Size: 261.06 MiB
:: Proceed with installation? [Y/n] y
:: Retrieving packages...
error: failed retrieving file 'mingw-w64-x86_64-qt5-5.12.1-5-any.pkg.tar.xz' from repo.msys2.org : Operation too slow. Less than 1 bytes/sec transferred the last 10 seconds
error: failed retrieving file 'mingw-w64-x86_64-qt5-5.12.1-5-any.pkg.tar.xz' from sourceforge.net : SSL certificate problem: unable to get local issuer certificate
error: failed retrieving file 'mingw-w64-x86_64-qt5-5.12.1-5-any.pkg.tar.xz' from www2.futureware.at : Operation too slow. Less than 1 bytes/sec transferred the last 10 seconds
error: failed retrieving file 'mingw-w64-x86_64-qt5-5.12.1-5-any.pkg.tar.xz' from mirror.yandex.ru : SSL certificate problem: unable to get local issuer certificate
warning: failed to retrieve some files
error: failed to commit transaction (download library error)
Errors occurred, no packages were upgraded.
按照这个，我的回购配置似乎没问题：
$ pacman-conf.exe
[options]
RootDir = /
DBPath = /var/lib/pacman/
CacheDir = /var/cache/pacman/pkg/
HookDir = /etc/pacman.d/hooks/
GPGDir = /etc/pacman.d/gnupg/
LogFile = /var/log/pacman.log
HoldPkg = pacman
Architecture = i686
CheckSpace
UseDelta = 0.000000
CleanMethod = KeepInstalled
SigLevel = PackageRequired
SigLevel = PackageTrustedOnly
SigLevel = DatabaseOptional
SigLevel = DatabaseTrustedOnly
LocalFileSigLevel = PackageOptional
LocalFileSigLevel = PackageTrustedOnly
[mingw32]
Usage = All
Server = http://repo.msys2.org/mingw/i686/
Server = https://sourceforge.net/projects/msys2/files/REPOS/MINGW/i686/
Server = http://www2.futureware.at/~nickoe/msys2-mirror/mingw/i686/
Server = https://mirror.yandex.ru/mirrors/msys2/mingw/i686/
[mingw64]
Usage = All
Server = http://repo.msys2.org/mingw/x86_64/
Server = https://sourceforge.net/projects/msys2/files/REPOS/MINGW/x86_64/
Server = http://www2.futureware.at/~nickoe/msys2-mirror/mingw/x86_64/
Server = https://mirror.yandex.ru/mirrors/msys2/mingw/x86_64/
[msys]
Usage = All
Server = http://repo.msys2.org/msys/i686/
Server = https://sourceforge.net/projects/msys2/files/REPOS/MSYS2/i686/
Server = http://www2.futureware.at/~nickoe/msys2-mirror/msys/i686/
Server = https://mirror.yandex.ru/mirrors/msys2/msys/i686/
有关的：
https://github.com/msys2/MINGW-packages/issues/1887
https://bbs.archlinux.org/viewtopic.php?id=199693
https://sourceforge.net/p/msys2/discussion/general/thread/8427aab0/
编辑 在我执行的评论中建议
pacman-mirrors ...
我的系统中似乎没有这样的可执行文件（脚本，别名等）另一方面，似乎我已经有了pacman-mirrors，并且它没有提供任何可执行文件（在至少在 msys2 中）。这个对吗？
$ updatedb
$ locate pacman-mirrors
/var/cache/pacman/pkg/pacman-mirrors-20180604-2-any.pkg.tar.xz
/var/lib/pacman/local/pacman-mirrors-20180604-2
/var/lib/pacman/local/pacman-mirrors-20180604-2/desc
/var/lib/pacman/local/pacman-mirrors-20180604-2/files
/var/lib/pacman/local/pacman-mirrors-20180604-2/mtree
$ pacman -Ql pacman-mirrors
pacman-mirrors /etc/
pacman-mirrors /etc/pacman.d/
pacman-mirrors /etc/pacman.d/mirrorlist.mingw32
pacman-mirrors /etc/pacman.d/mirrorlist.mingw64
pacman-mirrors /etc/pacman.d/mirrorlist.msys
$ pacman --needed -S bash pacman pacman-mirrors msys2-runtime
warning: bash-4.4.023-1 is up to date -- skipping
warning: pacman-5.1.2-2 is up to date -- skipping
warning: pacman-mirrors-20180604-2 is up to date -- skipping
warning: msys2-runtime-2.11.2-1 is up to date -- skipping
