Re: Bug#772665: produces broken cross compiler packages for mips64el

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On 12/09/2014 08:46 PM, Helmut Grohne wrote:
> Package: src:gcc-4.9
> Version: 4.9.2-5
> User: [email protected]
> Usertags: rebootstrap
> 
> When building a cross compiler for mips64el (and possibly other mips
> architectures), some binary packages are broken.
> 
> $ dpkg-deb -I ./libn32gcc-4.9-dev-mips64el-cross_4.9.2-5_all.deb 
>  new debian package, version 2.0.
>  size 86302 bytes: control archive=850 bytes.
>      503 bytes,    14 lines      control              
>      854 bytes,     9 lines      md5sums              
>  Package: libn32gcc-4.9-dev-mips64el-cross
>  Source: gcc-4.9
>  Version: 4.9.2-5
>  Architecture: all
>  Maintainer: Debian GCC Maintainers <[email protected]>
>  Installed-Size: 2484
>  Depends: gcc-4.9-base (= 4.9.2-5)
>  Recommends: 
>  Section: libdevel
>  Priority: optional
>  Homepage: http://gcc.gnu.org/
>  Description: GCC support library (n32 development files)
>   This package contains the headers and static library files necessary for
>   building C programs which use libgcc, libgomp, libquadmath, libssp or libitm.
> $
> 
> Please pay attention to the value of Recommends. It is an empty field,
> but the field is still there. This makes e.g. apt-get update choke:
> 
> | Reading package lists...
> | E: Problem parsing dependency Recommends
> | E: Error occurred while processing libn32gcc-4.9-dev-mips64el-cross (NewVersion2)
> | E: Problem with MergeList /var/lib/apt/lists/...
> | E: The package lists or status file could not be parsed or opened.
> 
> One wonders how an empty Recommends field can end up in the control
> file, when dpkg-gencontrol explicitly discards empty fields. In fact,
> the field is not empty after the dpkg-gencontrol invocation. Instead it
> contains:
> 
> | Recommends: libc6-dev-mips64el-cross (>= 2.13-5)
> 
> A bit later the following command is executed during build:
> 
> | sed -i -r '/^(Dep|Rec|Sug)/s/[a-z0-9-]+64[^,]+(, *|$)//g;/^(Dep|Rec|Sug)/s/libgcc1-mips64el-cross/libn32gcc1-mips64el-cross/;/^(Dep|Rec|Sug)/s/ *, *$//' debian/libn32gcc-4.9-dev-mips64el-cross/DEBIAN/control
> 
> The first command in the sed expression discards the libc dependency.
> 
> It comes from debian/rules.defs:
> 
> | ifneq (,$(filter $(DEB_TARGET_ARCH), mips mipsel mips64 mips64el mipsn32 mipsn32el))
> |   define cross_mangle_control
> | 	$(if $(findstring lib64,$(1)),sed -i -r '/^(Dep|Rec|Sug)/s/[a-z0-9-]+32[^$(COMMA)]+($(COMMA) *|$$)//g;/^(Dep|Rec|Sug)/s/$(p_lgcc)/$(p_l64gcc)/;/^(Dep|Rec|Sug)/s/ *$(COMMA) *$$//' debian/$(1)/DEBIAN/control,@:)
> | 	$(if $(findstring libn32,$(1)),sed -i -r '/^(Dep|Rec|Sug)/s/[a-z0-9-]+64[^$(COMMA)]+($(COMMA) *|$$)//g;/^(Dep|Rec|Sug)/s/$(p_lgcc)/$(p_ln32gcc)/;/^(Dep|Rec|Sug)/s/ *$(COMMA) *$$//' debian/$(1)/DEBIAN/control,@:)
> |   endef
> | else
> |   define cross_mangle_control
> |   endef
> | endif
> 
> I would like to provide a fix for this, but I fail to understand what
> this cross_mangle_control is supposed to achieve. The last time this was
> touched was #758408, where they caused other kind of havoc. An obvious
> idea is to replace "[a-z0-9-]+" with "lib", but without understanding
> why this was added initially, I cannot tell whether the prospective fix
> breaks the original use case.
> 
> Fact is that currently, the cross compilers generated for mips64el are
> broken.
> 
> Helmut
> 
> 

I can't remember. please ask the Debian mips maintainers. I assume, extending
the expression to entirely remove empty fields should work around this for now.