The fix works for me (using bash on openSUSE Tumbleweed).

Here is a possible fix:

Added a test, and tested with glibc 2.32 by manual editing config.h for USE_POSIX_THREADS_FROM_LIBC.
Works correctly.

Actually, I think there's a way to make gpg_strerror_r more usable on its own. I previously said

I find it quite difficult to use strerror_r and gpg_strerror_r. With having to guess and retry to get an appropriate buffer length, a wrapper which dynamically allocates the string seems to be needed.

Here is the documentation of the new way of single-threaded execution:
https://www.gnu.org/software/libc/manual/html_node/Single_002dThreaded.html

We also need to update m4/threadlib.m4.
Now, it's maintained in gnulib.
See the changes in:
https://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=commitdiff;h=12b5b00f93c6433c3df8176fc9674d7600f8b268

Applied and pushed.

(sorry, about my former comment, I only now realized that you did just that already in your original patch)

Updated:

diff --git a/configure.ac b/configure.ac
index 53a343b..f496729 100644
--- a/configure.ac
+++ b/configure.ac
@@ -82,6 +82,7 @@ AC_PROG_AWK
 AC_CHECK_TOOL(AR, ar, :)
 AC_USE_SYSTEM_EXTENSIONS

I guess the strcasecmp (nl_langinfo (CODESET), "UTF-8") results in some overhead, so if we do that what about kicking in only if a truncation is really to happen.

Thank you for your publishing your key of CB6BE1D0D7D1594A.
I applied and pushed your changes.

Thanks. Note, that the same code is in gnupg2 in common/exechelp-posix.c:736

In T5381#144927, @gniibe wrote:

For gpgrt_wait_processes, I modified it to skip invalid PID.
The change is: rE956c40f106ea: core: Fix gpgrt_wait_processes, by skipping invalid PID.

For gpgrt_wait_processes, I modified it to skip invalid PID.
The change is: rE956c40f106ea: core: Fix gpgrt_wait_processes, by skipping invalid PID.

Thanks. I understand that this is no big issue in the test code, but half of the code paths have proper cleaning already so fixing it once should save anyone in the future going through the same issues over and over again during our releases or anyone else who would run your code through static analyzer.

Thank you.
For get_attr_l, I pushed a fix as rE89a353f418f5: build: Fix gpgrt-config for handling 'Requires' field.

Actually I don't care about releasing resources for regression test failures.
The other missing free is for code which is commented out (#if 0) but should eventually be fixed.

Fixed in 1.42.

I was wrong in my last comment. Escaping by another \ is needed.

A PATH with spaces is too Windowish (or macOS). IIRC, we had once checks that the used directories have proper names; we can expect this for build environment. Spaces in file names are horrible from a security POV it is just to easy to get things wrong (hello ssh).

@gniibe Note that you also need to at least add the semicolons, as BSD sed is trying to parse "gp}" as substitution flags (which, honestly, makes more forward-compatible sense than GNU sed's behavior...).

Or, if we keep the code of newline (so that it will eventually support path with a space in future):

Thank you. Sorry for the use of GNU sed extension. It could be just a whitespace, if it's OK not to support path having a space.
sed -n -e "/^libraries/{s/libraries: =//;s/:/ /gp}") should work.

@gniibe OK, so... "worst case": I guess this worked? ;P

@gniibe Actually, I just realized that neither of the commands I provided work, as I failed to notice you were trying to also replace :'s with newlines (as I guess libraries from clang can return multiple paths). I'd momentarily edited my comment to just try to add back your colon replacement, before remembering you can't do that either: \n is a GNU sed extension. Hilariously, I'm always in contexts where I can assume I'm using bash (which isn't ok for configure), so I've never bothered to learn a technique that doesn't involve $'\n'... do you have a strategy for doing this replacement? :(

@gniibe Ah yeah, that was the commit I meant to reference when I said "--maybe caused by --", but then forgot to go back and fill in the commit hash ;P.

I wonder if this works in your use case:

diff --git a/m4/gpg-error.m4 b/m4/gpg-error.m4
index d910754e..aeedaf10 100644
--- a/m4/gpg-error.m4
+++ b/m4/gpg-error.m4
@@ -65,7 +65,7 @@ AC_DEFUN([AM_PATH_GPG_ERROR],
   min_gpg_error_version=ifelse([$1], ,1.33,$1)
   ok=no

If it is new, it may be the change of this commit rC8e3cd4c4677c: build: Update gpg-error.m4.

(To be clear, I also know enough about autoconf to not have been like, blocked from upgrading by this: overriding ac_cv_path_GPGRT_CONFIG worked, but I can't believe that's the intended way for someone to ensure they get the correct path for gpgrt-config ;P.)

@gniibe The problem is that the check seems to just find gpgrt-config from the path; like, I'm already passing --prefix and --host, but it is deciding to just arbitrarily pick up my system-wide copy of /usr/local/bin/gpgrt-config. Here's my entire configure invocation from that earlier failed build: note that the --prefix is the same as --with-gpg-error-prefix.

We are in transition from old gpg-error-config to new gpgrt-config. <-- This is the cause, while I tried to cover most use cases.

Pushed the change. Please test.

See the comment in rE13918d05a333: Allow building with --disable-threads. for ABI incompatibility.

When building with no threads support, I think that generating same lock-obj-pub-$host.h is just possible by this change.

Tell us the architecture(s) which doesn't support POSIX threads by uClibc.
Adding support for such an architecture would be the best.

Sorry, I was assuming uClibc were not supporting POSIX threads.

Thank you for more information.

I was not the author of the host "hacking" which has been committed to buildroot in 2016 by https://git.buildroot.net/buildroot/commit/package/?id=2f89476ad98b82ea9f914337b0050c4808082c82 so I can't really comment on it.
You can find more information here: https://patchwork.ozlabs.org/project/buildroot/patch/1451762923-15985-1-git-send-email-joerg.krause@embedded.rocks/
Especially, it seems that Jörg Krause started a discussion about this issue and proposed a patch to fix the architecture depends but it was never applied. Unfortunately, I wasn't able to find more information as it seems that links on comments.gmane.org are broken ...

Please note that the result with --host="arm-unknown-linux-gnueabi" for linux-uclibcgnueabih machine is different to the one of correctly generated version by gen-posix-lock-obj.c with USE_POSIX_THREADS undefined on the host.

I found that the use of $CC -print-file-name=crt1.o won't work with some cross compiler.
For example, on my system of Debian bullseye for cross compiler ppc64el, while it's for multiarch configuration, crt1.o is under GNU cross style directory: /usr/powerpc64le-linux-gnu/lib

I would understand your workaorund of using artifical --host intentionally.

This won't work in the context of buildroot as we're passing --host="arm-unknown-linux-gnueabi" to avoid the following build failure:

We also need to support the use case of GNU cross style, like when we build with MinGW toolchain.

For other libraries, like libgcrypt, it is mostly OK with old gpg-error.m4, because those libraries don't depend on new libgpg-error features.

Fixed GnuPG in rGe1e3f1db4660: build: Update gpg-error.m4. and rG985e85dc0e6c: build: Update gpg-error.m4..

Fixed more in rEd7fd25bbfb83: build: Fix the previous change..

Thank you for the report. I had expected *-*-linux* matches only to GNU/Linux (Linux kernel with GNU C library).

They are mandatory for gnupg but not for Libgcrypt and Libgpg-error. I guess we can fix that.

Because, threads are optional on uclibc as threads are not supported by all embedded targets.
libgpg-error was building perfectly fine without threads until version 1.40 as all pthread calls were protected by USE_POSIX_THREADS.
Should I understand from your answer that threads are now mandatory?

How does it come that you have a Linux kernel without threads? Or maybe the better question is why does libc not support threads?

Considered again, I realized that (1) is no need to check.

POSIX says so (use printf instead).
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/echo.html

iirc the advise from the GNU coding standards is to use printf(1) instead of trying to figure out how echo(1) works.

Thank you. I'll fix. Perhaps, I'll ignore old UNIXen like AIX 6.1, which has no way to echo with no newlines.

See T5192 for an updated release.

I know these troubles.

In T3189#117959, @gniibe wrote:

Do we need to expose the secmem routines, as a public interface of gpgrt?

I would find it useful. For example I'm making a utility that gets a passphrase with GPGME and gpg-agent, and would like to copy it into a buffer that lives on after closing the context.

Winepath starts calls the full Wine engine just convert file names to DOS format. This is used by libtool but if winepath can't be executed, it doesn't care. So the given solution (using /etc/alternatives/winepath -> /bin/false) can be used.

Release done.

For GNU/Linux, it's done.