[General] Unable to install packages when using termux proot distro

[WeirdGumi]

Describe the bug
I can't install any package at proot distro.
Can try using proot instead of proot-distro first. If there are issues, then I will change the title and comments to proot instead of proot-distro at that time.

To Reproduce

1. Install termux and open
2. Install the proot-distro package
3. Obtain the tarball from link and extract it to $HOME
4. Obtain eweos.sh from link and place it in the $PREFIX/etc/proot-distro directory
5. Run proot-distro install eweos
6. Run proot-distro login eweos
7. Install any package

Expected behavior

Additional context
Link: termux/proot-distro#642
Link: termux/proot-distro@98b6d71

~ $ proot-distro login eweos
[root@localhost ~]# pacman -S micro
resolving dependencies...
looking for conflicting packages...

Packages (1) micro-2.0.15-3

Total Download Size:    4.62 MiB
Total Installed Size:  12.11 MiB

:: Proceed with installation? [Y/n]
warning: couldn't find or create package cache, using /tmp/ instead
:: Retrieving packages...
 micro-2.0.15-3-a...     8.4 KiB  0.00   B/s --:
micro-2.0.15-3-a...    42.4 KiB  37.8 KiB/s 02:
micro-2.0.15-3-a...   224.0 KiB   219 KiB/s 00:
micro-2.0.15-3-a...   592.0 KiB   555 KiB/s 00:
micro-2.0.15-3-a...  1520.0 KiB  1917 KiB/s 00:
micro-2.0.15-3-a...     2.0 MiB  1974 KiB/s 00:
micro-2.0.15-3-a...     2.8 MiB  2.51 MiB/s 00:
micro-2.0.15-3-a...     3.2 MiB  2.31 MiB/s 00:
micro-2.0.15-3-a...     4.1 MiB  2.57 MiB/s 00:
micro-2.0.15-3-a...     4.6 MiB  1345 KiB/s 00
(0/1) checking keys in keyring                 
(1/1) checking keys in keyring                  
(0/1) checking package integrity               
(1/1) checking package integrity                
error: failed to read file /tmp/micro-2.0.15-3-aarch64.pkg.tar.zst: cannot open package file
error: failed to commit transaction (cannot open package file)
Errors occurred, no packages were upgraded.
[root@localhost ~]# pacman -U /tmp/micro-2.0.15-3-aarch64.pkg.tar.zst                           loading packages...
error: '/tmp/micro-2.0.15-3-aarch64.pkg.tar.zst': cannot open package file

[ziyao233]

~ $ proot-distro login eweos
[root@localhost ~]# pacman -S micro
resolving dependencies...
looking for conflicting packages...

Packages (1) micro-2.0.15-3

Total Download Size: 4.62 MiB
Total Installed Size: 12.11 MiB

:: Proceed with installation? [Y/n]
warning: couldn't find or create package cache, using /tmp/ instead
:: Retrieving packages...
micro-2.0.15-3-a... 8.4 KiB 0.00 B/s --:
micro-2.0.15-3-a... 42.4 KiB 37.8 KiB/s 02:
micro-2.0.15-3-a... 224.0 KiB 219 KiB/s 00:
micro-2.0.15-3-a... 592.0 KiB 555 KiB/s 00:
micro-2.0.15-3-a... 1520.0 KiB 1917 KiB/s 00:
micro-2.0.15-3-a... 2.0 MiB 1974 KiB/s 00:
micro-2.0.15-3-a... 2.8 MiB 2.51 MiB/s 00:
micro-2.0.15-3-a... 3.2 MiB 2.31 MiB/s 00:
micro-2.0.15-3-a... 4.1 MiB 2.57 MiB/s 00:
micro-2.0.15-3-a... 4.6 MiB 1345 KiB/s 00
(0/1) checking keys in keyring
(1/1) checking keys in keyring
(0/1) checking package integrity
(1/1) checking package integrity
error: failed to read file /tmp/micro-2.0.15-3-aarch64.pkg.tar.zst: cannot open package file
error: failed to commit transaction (cannot open package file)
Errors occurred, no packages were upgraded.
[root@localhost ~]# pacman -U /tmp/micro-2.0.15-3-aarch64.pkg.tar.zst loading packages...
error: '/tmp/micro-2.0.15-3-aarch64.pkg.tar.zst': cannot open package file

I doubt this is something specific to proot's implementation. The pacman's error isn't helpful, though.... Might you strace pacman for finding out what syscall is going wrong here?

[WeirdGumi]

~ $ proot-distro login eweos
[root@localhost ~]# pacman -S micro
resolving dependencies...
looking for conflicting packages...
Packages (1) micro-2.0.15-3
Total Download Size: 4.62 MiB
Total Installed Size: 12.11 MiB
:: Proceed with installation? [Y/n]
warning: couldn't find or create package cache, using /tmp/ instead
:: Retrieving packages...
micro-2.0.15-3-a... 8.4 KiB 0.00 B/s --:
micro-2.0.15-3-a... 42.4 KiB 37.8 KiB/s 02:
micro-2.0.15-3-a... 224.0 KiB 219 KiB/s 00:
micro-2.0.15-3-a... 592.0 KiB 555 KiB/s 00:
micro-2.0.15-3-a... 1520.0 KiB 1917 KiB/s 00:
micro-2.0.15-3-a... 2.0 MiB 1974 KiB/s 00:
micro-2.0.15-3-a... 2.8 MiB 2.51 MiB/s 00:
micro-2.0.15-3-a... 3.2 MiB 2.31 MiB/s 00:
micro-2.0.15-3-a... 4.1 MiB 2.57 MiB/s 00:
micro-2.0.15-3-a... 4.6 MiB 1345 KiB/s 00
(0/1) checking keys in keyring
(1/1) checking keys in keyring
(0/1) checking package integrity
(1/1) checking package integrity
error: failed to read file /tmp/micro-2.0.15-3-aarch64.pkg.tar.zst: cannot open package file
error: failed to commit transaction (cannot open package file)
Errors occurred, no packages were upgraded.
[root@localhost ~]# pacman -U /tmp/micro-2.0.15-3-aarch64.pkg.tar.zst loading packages...
error: '/tmp/micro-2.0.15-3-aarch64.pkg.tar.zst': cannot open package file

I doubt this is something specific to proot's implementation. The pacman's error isn't helpful, though.... Might you strace pacman for finding out what syscall is going wrong here?

strace.txt
strace2.txt

[ziyao233]

newfstatat(AT_FDCWD, "/var/cache/pacman/pkg/micro-2.0.15-3-aarch64.pkg.tar.zst", 0x7fd5799380, 0) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/tmp/micro-2.0.15-3-aarch64.pkg.tar.zst", {st_mode=S_IFREG|0644, st_size=4843923, ...}, 0) = 0
faccessat2(AT_FDCWD, "/tmp/micro-2.0.15-3-aarch64.pkg.tar.zst", R_OK, AT_SYMLINK_NOFOLLOW) = -1 ENETDOWN (Network is down)
openat(AT_FDCWD, "/usr/share/locale/en_US/LC_MESSAGES/libalpm.mo", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en/LC_MESSAGES/libalpm.mo", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en_US/LC_MESSAGES/libalpm.mo", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en/LC_MESSAGES/libalpm.mo", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en_US/LC_MESSAGES/pacman.mo", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en/LC_MESSAGES/pacman.mo", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
writev(2, [{iov_base="error: ", iov_len=7}, {iov_base=NULL, iov_len=0}], 2error: ) = 7
writev(2, [{iov_base="failed to read file /tmp/micro-2"..., iov_len=61}, {iov_base="cannot open package file", iov_len=24}], 2failed to read file /tmp/micro-2.
0.15-3-aarch64.pkg.tar.zst: cannot open package file) = 85

It's extremely strange for faccessat2() to return -ENETDOWN, and this is probably the reason that pacman fails:

        /* attempt to access the package file, ensure it exists */
        if(_alpm_access(handle, NULL, pkgfile, R_OK) != 0) {
                if(errno == ENOENT) {
                        handle->pm_errno = ALPM_ERR_PKG_NOT_FOUND;
                } else if(errno == EACCES) {
                        handle->pm_errno = ALPM_ERR_BADPERMS;
                } else {
                        handle->pm_errno = ALPM_ERR_PKG_OPEN;
                }
                return -1;
        }

pacman1 bails out with ALPM_ERR_PKG_OPEN when _alpm_access() fails, where the latter invokes faccessat(3). And musl always invokes faccessat2(2) when any flags (AT_SYMLINK_NOFOLLOW, for example, here) are specified for faccessat(3).

I suggest taking a look and figuring out why faccessat2(2) was failing with -ENETDOWN first. Though I haven't checked Linux kernel yet, it doesn't sound like not a correct behavior.

Will leave the issue open for reference.