Hi,

Building buildroot image causes a number of failures with the patchelf tool, for example from the output log:

>>>   Sanitizing RPATH in target tree
PER_PACKAGE_DIR=/media/SSD/Toolchains/my-toolchain/build/buildroot-2020.08/per-package /media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/support/scripts/fix-rpath target
terminate called after throwing an instance of 'std::out_of_range'
  what():  basic_string::substr: __pos (which is 72) > this->size() (which is 49)
/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/support/scripts/fix-rpath: line 61: 27743 Aborted                 ${PATCHELF} --make-rpath-relative "${rootdir}" ${sanitize_extra_args[@]} "${file}"
FAILED: /media/SSD/Toolchains/my-toolchain/build/buildroot-2020.08/host/bin/patchelf --make-rpath-relative '/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target' --no-standard-lib-dirs '/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target/usr/libexec/lzo/examples/lzopack'
terminate called after throwing an instance of 'std::out_of_range'
  what():  basic_string::substr: __pos (which is 72) > this->size() (which is 49)
/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/support/scripts/fix-rpath: line 61: 27750 Aborted                 ${PATCHELF} --make-rpath-relative "${rootdir}" ${sanitize_extra_args[@]} "${file}"
FAILED: /media/SSD/Toolchains/my-toolchain/build/buildroot-2020.08/host/bin/patchelf --make-rpath-relative '/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target' --no-standard-lib-dirs '/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target/usr/libexec/lzo/examples/lzotest'
terminate called after throwing an instance of 'std::out_of_range'
  what():  basic_string::substr: __pos (which is 72) > this->size() (which is 49)
/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/support/scripts/fix-rpath: line 61: 27766 Aborted                 ${PATCHELF} --make-rpath-relative "${rootdir}" ${sanitize_extra_args[@]} "${file}"
FAILED: /media/SSD/Toolchains/my-toolchain/build/buildroot-2020.08/host/bin/patchelf --make-rpath-relative '/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target' --no-standard-lib-dirs '/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target/usr/libexec/lzo/examples/simple'
terminate called after throwing an instance of 'std::out_of_range'
  what():  basic_string::substr: __pos (which is 72) > this->size() (which is 49)
/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/support/scripts/fix-rpath: line 61: 28047 Aborted                 ${PATCHELF} --make-rpath-relative "${rootdir}" ${sanitize_extra_args[@]} "${file}"
FAILED: /media/SSD/Toolchains/my-toolchain/build/buildroot-2020.08/host/bin/patchelf --make-rpath-relative '/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target' --no-standard-lib-dirs '/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target/usr/lib/libturbojpeg.so.0.2.0'
terminate called after throwing an instance of 'std::out_of_range'
  what():  basic_string::substr: __pos (which is 72) > this->size() (which is 49)
/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/support/scripts/fix-rpath: line 61: 28081 Aborted                 ${PATCHELF} --make-rpath-relative "${rootdir}" ${sanitize_extra_args[@]} "${file}"
FAILED: /media/SSD/Toolchains/my-toolchain/build/buildroot-2020.08/host/bin/patchelf --make-rpath-relative '/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target' --no-standard-lib-dirs '/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target/usr/lib/libjpeg.so.8.2.2'
terminate called after throwing an instance of 'std::out_of_range'
  what():  basic_string::substr: __pos (which is 72) > this->size() (which is 49)
/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/support/scripts/fix-rpath: line 61: 28096 Aborted                 ${PATCHELF} --make-rpath-relative "${rootdir}" ${sanitize_extra_args[@]} "${file}"
FAILED: /media/SSD/Toolchains/my-toolchain/build/buildroot-2020.08/host/bin/patchelf --make-rpath-relative '/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target' --no-standard-lib-dirs '/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target/usr/lib/libhistory.so.8.0'
terminate called after throwing an instance of 'std::out_of_range'
  what():  basic_string::substr: __pos (which is 72) > this->size() (which is 49)
/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/support/scripts/fix-rpath: line 61: 28118 Aborted                 ${PATCHELF} --make-rpath-relative "${rootdir}" ${sanitize_extra_args[@]} "${file}"
FAILED: /media/SSD/Toolchains/my-toolchain/build/buildroot-2020.08/host/bin/patchelf --make-rpath-relative '/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target' --no-standard-lib-dirs '/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target/usr/lib/libreadline.so.8.0'
touch /media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target/usr


I have managed to track down the error to a change brought in by the patch 0003-Add-option-to-make-the-rpath-relative-under-a-specif.patch.

Please see https://git.busybox.net/buildroot/tree/package/patchelf/0003-Add-option-to-make-the-rpath-relative-under-a-specif.patch#n257, at line 257.

At this point canonicalPath is "/media/SSD/Toolchains/my-toolchain/target/usr/lib" but rootDir is longer: "/media/SSD/Toolchains/my-toolchain/source/buildroot-2020.08/../../target", hence the exception.

It seems that the tool is missing the ability to resolve the "../" components of the rootDir path to make it canonical and I would guess that therefore the tool cannot be working in any case since the paths inside the target executable will never match the passed-in rootDir...

Cheers,
Andy