Reproduction steps

Try to clone a repository in a program on Android.

Expected behavior

Repository cloned

Actual behavior

error loading known_hosts error

Version of libgit2 (release number or SHA1)

The rust crate is libgit2-sys version 0.15.0+1.6.3, if that is any help. And the git2 crate is version .17.0.

Operating system(s) tested

Android

Notes

• this does not seem to to be the similar error as found on Windows.
• I got my error via the rust front end, but I do not think it is a rust issue, so I am raising it here.

Analysis

I am now doing env::set_var("HOME", "/data"); before I call libgit2, and now I am getting a different error message now: invalid or unknown remote ssh hostkey. (This comment is about the issue in the Android context).

When I do a rust env::var("HOME") , I get an error environment variable not found . But the libgit2 C code is using the environment variable to find the home directory (and from that the known hosts file).

The loading known hosts error is generated at libgit2/transports/ssh.c:545. It runs load_known_hostsand if the result is negative, it generates the error. load_known_hosts (435) does git_sysdir_expand_homedir_file, git_str_joinpath, libssh2_knownhost_init, andlibssh2_knownhost_readfile. It seems to be looking for $HOME/.ssh/known_hosts and then slurping this file in.

git_sysdir_expand_homedir_file (in sysdir.c:640) calls git_sysdir_find_homedir and git_str_joinpath; git_sysdir_find_homedir (622) calls git_sysdir_find_in_dirlist;, which (548) calls git_sysdir_get and then runs the result and sets the path (maybe it is making the path absolute). git_sysdir_get (490) does git_sysdir_check_selector (just an error check) and reads the git_sysdir__dirs (436) array for git_sysdir_guess_home_dirs.

git_sysdir_guess_home_dirs (324) is #ifdefed on GIT_WIN32. if not we call git__getenv or get_passwd_home. If we are not 'sandboxed' it calls git__getenv with "HOME"". Outside Windows, git__getenv (util.c:768) calls getenv.