Comment 13 for bug 2071468

libreoffice autopkgtests fail with the following error:

871s S=/tmp/autopkgtest.YSUwcU/build.7pH/src && I=$S/instdir && W=$S/workdir && x86_64-linux-gnu-gcc -Wl,-z,origin '-Wl,-rpath,$ORIGIN/../Library' -Wl,-rpath-link,$I/program -Wl,-z,defs -Wl,-rpath-link,/lib:/usr/lib -Wl,-z,combreloc -Wl,--hash-style=gnu -Wl,-Bsymbolic-functions -L$W/LinkTarget/StaticLibrary -L$I/sdk/lib -L$I/program -L$I/program -L$W/LinkTarget/Library -Wl,-Bsymbolic-functions -Wl,-z,relro -specs=/usr/share/dpkg/elf-package-metadata.specs $W/CObject/solenv/bin/concat-deps.o -Wl,--start-group -Wl,--end-group -Wl,--no-as-needed -o $W/LinkTarget/Executable/concat-deps
871s x86_64-linux-gnu-gcc: fatal error: environment variable ‘DEB_HOST_ARCH’ not defined

This is blocking openjdk-21 migration

[1] https://objectstorage.prodstack5.canonical.com/swift/v1/AUTH_0f9aae918d5b4744bf7b827671c86842/autopkgtest-oracular/oracular/amd64/libr/libreoffice/20240704_005705_46cf5@/log.gz