curl支持http3

git clone
cd nghttp3
autoreconf -i
./configure --prefix=/usr/local/nghttp3 --enable-lib-only
make
make install
cd ..

git clone
cd ngtcp2
autoreconf -i
 ./configure PKG_CONFIG_PATH=/usr/local/openssl111g/lib/pkgconfig:/usr/local/nghttp3/lib/pkgconfig LDFLAGS="-Wl,-rpath,/usr/local/openssl111g/lib" --prefix=/usr/local/ngtcp2 --enable-lib-only
make
make install
cd ..

git clone https://github.com/curl/curl
cd curl
./buildconf
LDFLAGS="-Wl,-rpath,/usr/local/openssl111g/lib" ./configure --with-ssl=/usr/local/openssl111g --with-nghttp3=/usr/local/nghttp3 --with-ngtcp2=/usr/local/ngtcp2
make

测试
src/curl --http3 -I
HTTP/3 200 
server: nginx
date: Mon, 25 Jan 2021 02:22:03 GMT
content-type: text/html; charset=UTF-8
vary: accept-encoding
x-powered-by: PHP/5.4.25
x-client-ip: 47.57.139.72
alt-svc: quic=":443"; h3-27=":443";h3-25=":443"; h3-T050=":443"; h3-Q050=":443";h3-Q049=":443";h3-Q048=":443"; h3-Q046=":443"; h3-Q043=":443"