sh-4.3$ ./pre-inst-env guix build --source libgit2 --substitute-urls=https://mirror.hydra.gnu.org
The following derivations will be built:
   /gnu/store/5szrmzmfgxk6pylk5fh9bk8apj4x8axf-libgit2-0.26.0.tar.xz.drv
   /gnu/store/mgh4yjxkxfyqmc7c61vwq4vs8v837602-libgit2-0.26.0.tar.gz.drv
@ build-started /gnu/store/mgh4yjxkxfyqmc7c61vwq4vs8v837602-libgit2-0.26.0.tar.gz.drv - x86_64-linux /var/log/guix/drvs/mg//h4yjxkxfyqmc7c61vwq4vs8v837602-libgit2-0.26.0.tar
.gz.drv.bz2

Starting download of /gnu/store/53lj4z9cavl7n27r89zjnvyd8fk854kj-libgit2-0.26.0.tar.gz
From https://github.com/libgit2/libgit2/archive/v0.26.0.tar.gz...
following redirection to `https://codeload.github.com/libgit2/libgit2/tar.gz/v0.26.0'...
 v0.26.0                                     4.2MiB/s 00:01 | 4.5MiB transferred
output path `/gnu/store/53lj4z9cavl7n27r89zjnvyd8fk854kj-libgit2-0.26.0.tar.gz' should have sha256 hash `1fdk9yhwvl1w1z71ykzcvgh4nsf8scxcbclz5anh98zpplmhmisa', instead has `
1b3figbhp5l83vd37vq6j2narrq4yl9pfw6mw0px0dzb1hz3jqka'
@ build-failed /gnu/store/mgh4yjxkxfyqmc7c61vwq4vs8v837602-libgit2-0.26.0.tar.gz.drv - 1 output path `/gnu/store/53lj4z9cavl7n27r89zjnvyd8fk854kj-libgit2-0.26.0.tar.gz' shou
ld have sha256 hash `1fdk9yhwvl1w1z71ykzcvgh4nsf8scxcbclz5anh98zpplmhmisa', instead has `1b3figbhp5l83vd37vq6j2narrq4yl9pfw6mw0px0dzb1hz3jqka'
cannot build derivation `/gnu/store/5szrmzmfgxk6pylk5fh9bk8apj4x8axf-libgit2-0.26.0.tar.xz.drv': 1 dependencies couldn't be built
guix build: error: build failed: build of `/gnu/store/5szrmzmfgxk6pylk5fh9bk8apj4x8axf-libgit2-0.26.0.tar.xz.drv' failed