"Coding" question (to overcome xbpx-src pkg compiling error)

[gc-user]

As suspected in the past, there would come a day when pam_zfscrypt might stop compiling against a newer zfs version....

Well, that day has come with zfs 2.3.2, apparently.

Now, the pam_zfscrypt version I have installed already seems to work with zfs v2.3.2 (I can use the system without apparent problems - I would assume, if the package wouldn't work anymore, I shouldn't be able to login as the package would not be able to decrypt and mount my home directory (unless some other void package does the same...?)), but just to be sure, I wanted to build the package against the v2.3.2 anew.

Trying to compile, I get the following error message(s) (bold doesn't seem to work within "code", so I isolated the lines in question by adding empty lines before and after):

./xbps-src pkg pam_zfscrypt
=> xbps-src: updating repositories for host (x86_64)...
[*] Updating repository `https://repo-default.voidlinux.org/current/bootstrap/x86_64-repodata' ...
[*] Updating repository `https://repo-default.voidlinux.org/current/x86_64-repodata' ...
[*] Updating repository `https://repo-default.voidlinux.org/current/nonfree/x86_64-repodata' ...
[*] Updating repository `https://repo-default.voidlinux.org/current/debug/x86_64-repodata' ...
[*] Updating repository `https://repo-default.voidlinux.org/current/multilib/bootstrap/x86_64-repodata' ...
[*] Updating repository `https://repo-default.voidlinux.org/current/multilib/x86_64-repodata' ...
[*] Updating repository `https://repo-default.voidlinux.org/current/multilib/nonfree/x86_64-repodata' ...
=> xbps-src: updating software in / masterdir...
=> xbps-src: cleaning up / masterdir...
=> pam_zfscrypt-0.2.0_5: removing autodeps, please wait...
=> pam_zfscrypt-0.2.0_5: building with [gnu-makefile] for x86_64...
   [target] pam-devel-1.5.3_4: found (https://repo-default.voidlinux.org/current)
   [target] zfs-devel-2.3.2_1: found (https://repo-default.voidlinux.org/current)
   [runtime] pam-1.5.3_4: found (https://repo-default.voidlinux.org/current)
=> pam_zfscrypt-0.2.0_5: installing target dependencies: pam-devel-1.5.3_4 zfs-devel-2.3.2_1 ...
=> pam_zfscrypt-0.2.0_5: running pre-build hook: 02-script-wrapper ...
=> pam_zfscrypt-0.2.0_5: running do_build ...
rm -rf ./build
mkdir -p ./build
cc -fstack-clash-protection -D_FORTIFY_SOURCE=2 -mtune=generic -O2 -pipe  -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -fPIC -Iinclude  -ffile-prefix-map=/builddir/pam_zfscrypt-0.2.0=. -isystem/usr/include/libzfs -isystem/usr/include/libspl -c -o build/pam_zfscrypt.o src/pam_zfscrypt.c
cc -fstack-clash-protection -D_FORTIFY_SOURCE=2 -mtune=generic -O2 -pipe  -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -fPIC -Iinclude  -ffile-prefix-map=/builddir/pam_zfscrypt-0.2.0=. -c -o build/zfscrypt_config.o src/zfscrypt_config.c
cc -fstack-clash-protection -D_FORTIFY_SOURCE=2 -mtune=generic -O2 -pipe  -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -fPIC -Iinclude  -ffile-prefix-map=/builddir/pam_zfscrypt-0.2.0=. -isystem/usr/include/libzfs -isystem/usr/include/libspl -c -o build/zfscrypt_context.o src/zfscrypt_context.c
cc -fstack-clash-protection -D_FORTIFY_SOURCE=2 -mtune=generic -O2 -pipe  -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -fPIC -Iinclude  -ffile-prefix-map=/builddir/pam_zfscrypt-0.2.0=. -isystem/usr/include/libzfs -isystem/usr/include/libspl -c -o build/zfscrypt_dataset.o src/zfscrypt_dataset.c
src/zfscrypt_dataset.c: In function 'zfscrypt_dataset_properties_get_user':



**src/zfscrypt_dataset.c:149:55: error: passing argument 3 of 'nvlist_lookup_string' from incompatible pointer type [-Wincompatible-pointer-types]
  149 |         err = nvlist_lookup_string(prop, ZPROP_VALUE, (char **) user);
      |                                                       ^~~~~~~~~~~~~~
      |                                                       |
      |                                                       char **
In file included from /usr/include/libzfs/libnvpair.h:30,
                 from /usr/include/libzfs/libzfs.h:40,
                 from include/zfscrypt_dataset.h:2,
                 from src/zfscrypt_dataset.c:1:
/usr/include/libzfs/sys/nvpair.h:237:5: note: expected 'const char **' but argument is of type 'char **'
  237 |     const char **);
      |     ^~~~~~~~~~~~~**



src/zfscrypt_dataset.c: In function 'zfscrypt_dataset_load_key':
src/zfscrypt_dataset.c:74:5: warning: ignoring return value of 'pipe' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |     pipe(in_fds);
      |     ^~~~~~~~~~~~
src/zfscrypt_dataset.c:87:9: warning: ignoring return value of 'write' declared with attribute 'warn_unused_result' [-Wunused-result]
   87 |         write(in_fds[1], self->key, strlen(self->key));
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/zfscrypt_dataset.c: In function 'zfscrypt_dataset_change_key':
src/zfscrypt_dataset.c:103:5: warning: ignoring return value of 'pipe' declared with attribute 'warn_unused_result' [-Wunused-result]
  103 |     pipe(in_fds);
      |     ^~~~~~~~~~~~
src/zfscrypt_dataset.c:115:9: warning: ignoring return value of 'write' declared with attribute 'warn_unused_result' [-Wunused-result]
  115 |         write(in_fds[1], self->new_key, strlen(self->new_key));
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
make: *** [Makefile:35: build/zfscrypt_dataset.o] Error 1
=> ERROR: pam_zfscrypt-0.2.0_5: do_build: '${make_cmd} CC="$CC" CXX="$CXX" LD="$LD" AR="$AR" RANLIB="$RANLIB" CPP="$CPP" AS="$AS" OBJCOPY="$OBJCOPY" OBJDUMP="$OBJDUMP" CFLAGS="$CFLAGS" CXXFLAGS="$CXXFLAGS" LDFLAGS="$LDFLAGS" PREFIX=/usr prefix=/usr ${makejobs} ${make_build_args} ${make_build_target}' exited with 2
=> ERROR:   in do_build() at common/build-style/gnu-makefile.sh:9

Now, I'm not a programmer, so all I can do is read the error message and the try to figure out what I can do to overcome an error.

So, I tested compiling the package again after changing

err = nvlist_lookup_string(prop, ZPROP_VALUE, (char **) user);

to

err = nvlist_lookup_string(prop, ZPROP_VALUE, (const char **) user);

in line 149 of void-packages/masterdir-x86_64/builddir/pam_zfscrypt-0.2.0/src/zfscrypt_dataset.c.

After that little change the build process runs through and the packages is build.

My questions would be:

1. Does what I did sound / look ok?
2. Should I be concerned about the warnings (and try to fix them, too)? Because those were still present in the "successful" build process after changing that one line.

Thank you very much for your help!

[gc-user]

Update:

Trying to compile pam_zfscrypt against previous versions of zfs (v2.2.7, v2.3.0, v2.3.1) to see if they also had those warnings I learned that they (now) even have the error. To me that means that those messages come from the "compiler" (gnu_makefile?) rather than zfs, because I was able to build pam_zfscrypt against zfs in February of this year - when zfs v2.3.0 was current.

However, "make" (assuming that is used for gnu_makefile build_syle)) hasn't changed on void since 2023.

So, I'm not sure what to make of it.

[gc-user]

Another update:

With the help of re-reading the warning / error messages carefully and using internet search I could "fix" at least some of the warnings and the error(s) so that I was able to successfully build the package against the (then) current version(s) of zfs.

I would assume that some updated compiler wouldn't accept previously accepted syntax anymore and hence give out warnings and errors.

[gc-user]

I'll close this for now - until I encounter an issue I can't fix myself in the future and have to resurrect this one... :-)