i know this question has already been asked, but it didn't have an answer that worked for me and i cannot comment as i do not have enough reputation.
I'm not able to install php-gd extension on my server.
i have php 7.1 on debian 8
here is the command i ran to try install it
sudo apt-get install php7.1-gd
and here is the output
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
libdrm-intel1 libdrm-nouveau2 libdrm-radeon1 libdrm2 libelf1 libfontenc1 libgl1-mesa-dri libgl1-mesa-glx
libglapi-mesa libice6 libpciaccess0 libsm6 libtxc-dxtn-s2tc0 libutempter0 libx11-xcb1 libxaw7 libxcb-dri2-0
libxcb-dri3-0 libxcb-glx0 libxcb-present0 libxcb-shape0 libxcb-sync1 libxcomposite1 libxcursor1 libxdamage1
libxfixes3 libxfont1 libxft2 libxi6 libxinerama1 libxkbfile1 libxmu6 libxrandr2 libxrender1 libxshmfence1 libxt6
libxtst6 libxv1 libxxf86dga1 libxxf86vm1 vnc4server x11-apps x11-common x11-session-utils x11-utils x11-xkb-utils
x11-xserver-utils xbase-clients xbitmaps xfonts-base xfonts-encodings xfonts-utils xinit xterm
Use 'apt-get autoremove' to remove them.
The following NEW packages will be installed:
php7.1-gd
0 upgraded, 1 newly installed, 0 to remove and 164 not upgraded.
Need to get 27.7 kB of archives.
After this operation, 138 kB of additional disk space will be used.
Get:1 https://packages.sury.org/php/ jessie/main php7.1-gd amd64 7.1.15-1+0~20180306120119.15+jessie~1.gbp78327e [27.7 kB]
Err https://packages.sury.org/php/ jessie/main php7.1-gd amd64 7.1.15-1+0~20180306120119.15+jessie~1.gbp78327e
HttpError404
E: Failed to fetch https://packages.sury.org/php/pool/main/p/php7.1/php7.1-gd_7.1.15-1+0~20180306120119.15+jessie~1.gbp78327e_amd64.deb HttpError404
any ideas how to fix it please?