i686-linux-gnu cross-compiler cannot find libgcc_s [core-updates]

I tested this on 683eb7c5b118440001b89944563603a39fc2ac05.

The problem does not occur on master.

How to reproduce:

# --target=aarch64-linux-gnu also fails, but that's another issue

./pre-inst-env guix build --target=i686-linux-gnu hello --keep-failed

Error message (during 'configure' phase):

checking for i686-linux-gnu-gcc... i686-linux-gnu-gcc

checking whether the C compiler works... no

configure: error: in `/tmp/guix-build-hello-2.10.drv-0/hello-2.10':

configure: error: C compiler cannot create executables

See `config.log' for more details

error: in phase 'configure': uncaught exception:

%exception #<&invoke-error program: "/gnu/store/kpkbyk7jlw6n5z3jkbia9mcr0bhflzbf-bash-minimal-5.1.8/bin/bash" arguments: ("./configure" "CC_FOR_BUILD=gcc"

"CONFIG_SHELL=/gnu/store/kpkbyk7jlw6n5z3jkbia9mcr0bhflzbf-bash-minimal-5.1.8/bin/bash" "SHELL=/gnu/store/kpkbyk7jlw6n5z3jkbia9mcr0bhflzbf-bash-minimal-5.1.8/bin/bash" "

--prefix=/gnu/store/wmkbla5nncld4rdyqkwc9lw9kzypvdab-hello-2.10" "--enable-fast-install" "--build=x86_64-unknown-linux-gnu" "--host=i686-linux-gnu") exit-status: 77 term-signal: #f stop-signal: #f>

phase `configure' failed after 3.1 seconds

From 'config.log':

configure:4014: checking whether the C compiler works

configure:4036: i686-linux-gnu-gcc conftest.c >&5

i686-linux-gnu-ld: cannot find -lgcc_s

i686-linux-gnu-ld: cannot find -lgcc_s

collect2: error: ld returned 1 exit status

configure:4040: $? = 1

configure:4078: result: no

configure: failed program was:

| /* confdefs.h */

| #define PACKAGE_NAME "GNU Hello"

| #define PACKAGE_TARNAME "hello"

| #define PACKAGE_VERSION "2.10"

| #define PACKAGE_STRING "GNU Hello 2.10"

| #define PACKAGE_BUGREPORT "bug-hello@gnu.org"

| #define PACKAGE_URL "http://www.gnu.org/software/hello/"

| #define PACKAGE "hello"

| #define VERSION "2.10"

| /* end confdefs.h. */

|

| int

| main ()

| {

|

| ;

| return 0;

| }

configure:4083: error: in `/tmp/guix-build-hello-2.10.drv-0/hello-2.10':

configure:4085: error: C compiler cannot create executables

Issue:

Somehow, the C cross-compiler does not find "libgcc_s".

Look at CROSS_LIBRARY_PATH and LIBRARY_PATH in /tmp/[...]/environment-variables,

we have (line breaks added):

export CROSS_LIBRARY_PATH=

/gnu/store/glc86jl13yj70k2h4mm3pqwff351mxav-glibc-cross-i686-linux-gnu-2.33/lib:

/gnu/store/wk761j8qqq7yf949wyxjgcbqxcx574nf-glibc-cross-i686-linux-gnu-2.33-static/lib

export LIBRARY_PATH=

/gnu/store/w6ydl1fjxhkc69cs90vmg3g48vwcy59w-binutils-cross-i686-linux-gnu-2.36.1/lib:

/gnu/store/lv8zj6sl3fc6db2ljq10haba3sfhvq6b-bzip2-1.0.8/lib:

/gnu/store/hhg5z17xyfj7zvg864br41nsj6g918ym-xz-5.2.5/lib:

/gnu/store/pnj9pzyk4ajs9a245krx5l4sp4p8xwyk-file-5.39/lib:

/gnu/store/0amam2n0vjb62zh6jssb9pjnwcf302hw-gawk-5.1.0/lib:

/gnu/store/3fasjd1jnnm6vhyff5wb3kkahnxzbl49-binutils-2.36.1/lib:

/gnu/store/mf4kmmhka2dagnna6a0h4fciz5ijaxsn-glibc-2.33/lib:

/gnu/store/dj2p4mwp6gwbx8fpd6gqsj2c307mm6sp-glibc-2.33-static/lib:

/gnu/store/dxplmvm0xf8z968m3lbwzizc95h9nldc-glibc-utf8-locales-2.33/lib

When I run "ls -l" on each of these directories, I notice none of these

have a "libgcc_s.so" file. So it's not very surprising GNU ld (via GCC) cannot find it.

Now, where could we find "libgcc_s.so"?

I found it in

/gnu/store/6b4sgmqd3nrajbx47zryi0n4s08sfrb6-gcc-cross-i686-linux-gnu-8.5.0/i686-linux-gnu/lib/

By explicitely passing "-L/gnu/store/6b4sgmqd3nrajbx47zryi0n4s08sfrb6-gcc-cross-i686-linux-gnu-8.5.0/i686-linux-gnu/lib/",

the C program compiles. So, I guess we need to add that directory to CROSS_LIBRARY_PATH. Or ...

Let's test.

/gnu/store/6b4sgmqd3nrajbx47zryi0n4s08sfrb6-gcc-cross-i686-linux-gnu-8.5.0/bin/i686-linux-gnu-gcc -dumpspecs

Output (only a part shown)

*lib:

%{!mandroid|tno-android-ld:-L/gnu/store/glc86jl13yj70k2h4mm3pqwff351mxav-glibc-cross-i686-linux-gnu-2.33/lib %{!static:-rpath=/gnu/store/glc86jl13yj70k2h4mm3pqwff351mxav-glibc-cross-i686-linux-gnu-

2.33/lib %{!static-libgcc:-rpath=/gnu/store/53i7hxqwf3apvz77bsapjvrigjiimg29-gcc-cross-i686-linux-gnu-8.5.0-lib/i686-linux-gnu/lib -lgcc_s}} %{pthread:-lpthread} %{shared:-lc} %{!shared:%{profile:-

lc_p}%{!profile:-lc}};:%{shared:-lc} %{!shared:%{profile:-lc_p}%{!profile:-lc}} %{!static: -ldl}}

Curiously, /gnu/store/53i7hxqwf3apvz77bsapjvrigjiimg29-gcc-cross-i686-linux-gnu-8.5.0-lib/i686-linux-gnu/lib

is actualy present! Let's compile in verbose mode.

$ i686-linux-gnu-gcc -v conftest.o

Output:

gcc-cross-i686-linux-gnu-8.5.0/libexec/gcc/i686-linux-gnu/:/gnu/store/[...]-gcc-cross-i686-linux-gnu-8.5.0-lib/lib/gcc/i686-linux-gnu/8.5.0/:/gnu/store/[...]-gcc-cross-i686-linux-gnu-8.5.0-

lib/lib/gcc/i686-linux-gnu/

lib/lib/gcc/i686-linux-gnu/8.5.0/:/gnu/store/[...]-glibc-cross-i686-linux-gnu-2.33/lib

-plugin-opt=/gnu/store/[...]-gcc-cross-i686-linux-gnu-8.5.0/libexec/gcc/i686-linux-gnu/8.5.0/lto-wrapper -plugin-opt=-fresolution=/tmp/guix-build-hello-2.10.drv-0/ccxP5sep.res -plugin-opt=-pass-

through=-lgcc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s --sysroot=/ --eh-

frame-hdr -m elf_i386 -dynamic-linker /gnu/store/[...]-glibc-cross-i686-linux-gnu-2.33/lib/ld-linux.so.2 /gnu/store/[...]-glibc-cross-i686-linux-gnu-2.33/lib/crt1.o /gnu/store/[...]-glibc-cross-i686-

linux-gnu-2.33/lib/crti.o /gnu/store/[...]-gcc-cross-i686-linux-gnu-8.5.0-lib/lib/gcc/i686-linux-gnu/8.5.0/crtbegin.o -L/gnu/store/[...]-glibc-cross-i686-linux-gnu-2.33/lib -L/gnu/store/[...]-glibc-

cross-i686-linux-gnu-2.33-static/lib -L/gnu/store/[...]-gcc-cross-i686-linux-gnu-8.5.0-lib/lib/gcc/i686-linux-gnu/8.5.0 -L/gnu/store/[...]-glibc-cross-i686-linux-gnu-2.33/lib conftest.o -lgcc --as-

needed -lgcc_s --no-as-needed -L/gnu/store/[...]-glibc-cross-i686-linux-gnu-2.33/lib -rpath=/gnu/store/[...]-glibc-cross-i686-linux-gnu-2.33/lib -rpath=/gnu/store/[...]-gcc-cross-i686-linux-gnu-8.5.0-

lib/i686-linux-gnu/lib -lgcc_s -lc -lgcc --as-needed -lgcc_s --no-as-needed /gnu/store/[...]-gcc-cross-i686-linux-gnu-8.5.0-lib/lib/gcc/i686-linux-gnu/8.5.0/crtend.o /gnu/store/[...]-glibc-cross-i686-

linux-gnu-2.33/lib/crtn.o

What went wrong here? I took a look at the folowing entry in CROSS_LIBRARY_PATH:

/gnu/store/[...]-gcc-cross-i686-linux-gnu-8.5.0-lib/lib/gcc/i686-linux-gnu/8.5.0/.

In this directory, there is a "libgcc.a", but not a "libgcc_s.so"! So, we have

a static libgcc library, but not a dynamic libgcc_s library!

To be investigated ... or worked around by tweaking CROSS_LIBRARY_PATH ...

Some digging.

Currently, there exists a gcc-7-cross-toolexeclibdir.patch.

It is applied to gcc 6 and gcc 7 but not gcc 8.

Looking at 'cross-gcc' in 'gnu/packages/cross-base.scm',

we have

(patches

(append

(origin-patches (package-source xgcc))

(append (cond

((version>=? (package-version xgcc) "8.0")

(search-patches "gcc-8-cross-environment-variables.patch"))

((version>=? (package-version xgcc) "6.0")

(search-patches "gcc-7-cross-toolexeclibdir.patch"

"gcc-6-cross-environment-variables.patch"))

(else

(search-patches "gcc-cross-environment-variables.patch")))

(cross-gcc-patches xgcc target))))

The patches for gcc-8+ were introduced in 83b0a7f41bccb7b46f1d443e80a22c61a3ff92bc.

Seems like we forgot to include gcc-7-cross-toolexeclibdir.patch!

I tried to add this patch, but the patch doesn't apply to the gcc 8 code,

so I guess I'll have to port it to gcc 8.

So I cloned the git repository of GCC, and it appears toolexeclibdir is currently

in GCC 8! But perhaps a mistake has been made somewhere ... to be investigated.

(Now looking at libgcc/configure.ac)

Maxime Devos schreef op di 08-06-2021 om 10:41 [+0200]:

I have found a solution: passing --with-slibdir to GCC's configure

script. Not sure if that's the proper solution though. GNU Hello

now builds succesfully! I'll test with a few more packages later

and then ‘formally’ submit the patch (after writing a commit message).

Greetings,

Maxime.

Hi,

Maxime Devos <maximedevos@telenet.be> skribis:

“i686-linux-gnu” is not among the supported cross-compilation triplets,

which are roughly those that appears in (@ (gnu ci) %cross-targets).

It’s rarely useful to cross-compile to i686-linux-gnu because you can

just build natively on an x86_64-linux-gnu machine:

guix build -s i686-linux hello

All this to say, I don’t think we should spend energy on the

i686-linux-gnu cross toolchain.

WDYT?

Ludo’.

Maxime Devos <maximedevos@telenet.be> skribis:

Could you check whether aarch64-linux-gnu or armhf-linux-gnueabihf (say)

have the problem, and whether this patch addresses it?

Thanks,

Ludo’.

Ludovic Courtès schreef op vr 18-06-2021 om 11:33 [+0200]:

This patch (passing --with-slibdir) doesn't actualy fully work

(when cross-compiling to i686-linux-gnu from a x86_64-linux),

as libstdc++ is not installed in the right place

(and other stuff like libusan, but those are less critical IMHO).

I sent a more complete (and hackier) patch as part of the

patch series for implementing cross-compilation in Meson

(not really the right place, I know, but it's hard to test

cross-compilation when the cross-compiler is broken),

see [PATCH v3 core-updates 36/37: Fix cross-compiler for i686-linux-gnu]

(https://issues.guix.gnu.org/49025.

I'll send a mail to bug#49025 asking people to respond about

that patch at bug#48913, to keep things separate.

I'll test whether aarch64-linux-gnu and armhf-linux-gnueabihf

have the same problem and whether the patch (from bug#48913)

addresses it.

Greetings,

Maxime.

Ludovic Courtès schreef op vr 18-06-2021 om 11:33 [+0200]:

The second triplet appears to be invalid.

$ ./pre-inst-env guix build hello --target=armhf-linux-gnueabihf

(during the build of binutils-cross-armhf-linux-gnuabihf)

$ ./pre-inst-env guix build hello --target=arm-linux-gnueabihf

# ^ replacing armhf with arm

Greetings,

Maxime.

Ludovic Courtès schreef op vr 18-06-2021 om 11:33 [+0200]:

I tried

./pre-inst-env guix build hello --target=arm-linux-gnueabihf

with the revised patch, but it fails building

/gnu/store/l6yhx9axhfbdmk7cm8cf9mql4h8mrqmc-glibc-cross-arm-linux-gnueabihf-2.33.drv.

I'll update to latest core-updates and retry with and without the patch.

Build log attached. There is an ICE, and dmesg doesn't note any OOM errors.

Greetings,

Maxime.

Ludovic Courtès schreef op vr 18-06-2021 om 11:32 [+0200]:

Agreed, closing. Though if someone has the same issue when building

a cross-compiler from, say, aarch64 to i686, then I'd recommend reopening

it.

Greetings,

Maxime.