From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0564F3DAAB8; Fri, 9 Oct 2026 05:11:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791522676; cv=none; b=Z8G9uI7v6L8yJSYkq5Kn3flLt1uCiW1Qw0RZ5UP6Y8uQPFIUosDmVolvIDSneXRDkDFZpD1K9gZKYsMpco/KyI3fFkThX5SWApHqkhcsD/fichp/NwyAdRDzYMdiYlPOJm/Xd/vfIzDuiSFEcYkJx8vbLo/uE/mUop7+4qPP1WU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791522676; c=relaxed/simple; bh=RzkyiB51qcBMO9M9pe/skL3kPgqjbkSNBulhFPoDd80=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bwo6Oi2m5DTnsVjcokZhEoydNOKIJaHB8YJ2EbM8WweOvs+YRnMjL21K5gG0VaEYm5hx0UDJXTqZVUQgj6Cku37d8oM6YOfbVSOyhfrxR5ehleOwM0H0e8jM9D92u8XnmWllFUIY1+TDzqZ5AiYGl/igGk06VRj6AFSxQngarZQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=B8uiIdEZ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="B8uiIdEZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D0FD1F000FF; Fri, 9 Oct 2026 05:11:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791522674; bh=iIl2Cg3RK/sSQdjUu8PWtqQJorCmflCcV7loVaKT08s=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=B8uiIdEZtT5l8fJqbwJZ3epIk/LuQCZNjgx7+XWz+f6NcDedzqismbSB7oS7ckwL2 4UiFs+6GvlLCUujipOaktLe7HMTk8Qaka7QiaqDeQdnJbfWinFd9Er+6ScUCYkJ2R8 6B2h+MSKe8q+ZtKlXP2lfEMRzSdrllKQd/vCUjPusP/NSh7J/O1TTtOmF9ug6Rey1C JtzAkZ/fdL5wny0HDue3cvJyTy3miIy2nStVtQVt3Vua7MKGFcExldGDBrC3UJNK+S is3anucNfefxptlwbf4uOyHcTktwmjp9PVANNOOPKx0BpJPOVruq9Vc+fLmMy4gvOl D464FsKUEDE4Q== Date: Thu, 8 Oct 2026 22:11:14 -0700 From: Kees Cook To: "Paul E. McKenney" Cc: Lorenzo Stoakes , Nicolas Schier , Jonathan Corbet , Mauro Carvalho Chehab , Manuel Ebner , Nathan Chancellor , linux-kbuild@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, workflows@vger.kernel.org, Mark Brown , linux-next@vger.kernel.org Subject: Re: [BUG] Build failure in next-20261007 and next-20261008 Message-ID: <202610082200.752C6C08A5@keescook> References: <0ddb5e5e-f801-444c-aa98-0cfe814a3026@paulmck-laptop> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0ddb5e5e-f801-444c-aa98-0cfe814a3026@paulmck-laptop> On Thu, Oct 08, 2026 at 05:56:21PM -0700, Paul E. McKenney wrote: > Building a kernel on CentOS Stream 9 from next-20261007 and next-20261008 > (and maybe others?) on an x86 or arm64 system results in a strange > build failure featuring: > > WARNING: Unable to reopen jobserver read-side pipe: FileNotFoundError(2, 'No such file or directory') What are your make and python versions? (Oh, the answer is going to be "CentOS-patched make 4.3") > The failing systems have a pigz command (which complains bitterly when > run without arguments), and the immune system does not. On the failing > systems, "pigz --version" gives me "pigz 2.5". > > Do I need a specific version of pigz? Does this commit need a > version-number check? Are my systems pigz-intolerant? ;-) > > Less flippantly, is this a known problem? If not, what debugging > information can I provide? Having pigz just means the parallelism logic kicks in, so I'm suspecting something in scripts/jobserver-exec. That would point to something specific to python or make. I haven't seen this reported before, no. Ah, and before I could even finish writing this email, my ever helpful LLM has reported: "pre-4.4 make (like CentOS's 4.3) closes jobserver pipe descriptors in non-recursive recipes but still exports --jobserver-auth=R,W via MAKEFLAGS, whereas 4.4+ uses a named FIFO instead, explaining why it doesn't appear here." And has further found that this is CentOS-specific, since they appear to have incorrectly backported a patch ("make-4.3-cloexec.patch"), as stock make 4.3 doesn't have this problem. I'll go figure out if there is some proper way to work around CentOS's broken make... (And given this, I would suspect you can't do a '-j...' build of the "htmldocs" target either?) -Kees -- Kees Cook