Makefile.PL fails with no '.' in @INC

[dcollinsn]

On current bleadperl with no '.' in @inc:

Output from '/home/cpan4/install/bin/perl Makefile.PL':

Can't locate inc/Module/Install.pm in @INC (you may need to install the inc::Module::Install module) (@INC contains: /tmp/CPAN-Reporter-lib-oHTJ /home/cpan4/install/lib/perl5/site_perl/5.26.0/x86_64-linux-thread-multi-ld /home/cpan4/install/lib/perl5/site_perl/5.26.0 /home/cpan4/install/lib/perl5/5.26.0/x86_64-linux-thread-multi-ld /home/cpan4/install/lib/perl5/5.26.0) at Makefile.PL line 2.
BEGIN failed--compilation aborted at Makefile.PL line 2.

------------------------------
PREREQUISITES
------------------------------

Prerequisite modules loaded:

configure_requires:

    Module              Need Have   
    ------------------- ---- -------
    ExtUtils::MakeMaker 6.42 7.25_01


------------------------------
ENVIRONMENT AND OTHER CONTEXT
------------------------------

Environment variables:

    AUTOMATED_TESTING = 1
    HARNESS_OPTIONS = j3
    LANG = en_US.UTF-8
    PATH = /usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games
    PERL = /home/cpan4/install/bin/perl
    PERL5LIB = 
    PERL5OPT = -I/tmp/CPAN-Reporter-lib-oHTJ -MDevel::Autoflush
    PERL5_CPANPLUS_IS_RUNNING = 16984
    PERL5_CPAN_IS_EXECUTING = /home/cpan4/.cpan/build/Text-Markdown-1.000031-0/Makefile.PL
    PERL5_CPAN_IS_RUNNING = 16984
    PERL5_CPAN_IS_RUNNING_IN_RECURSION = 18389,16984
    PERL_AUTOINSTALL = --defaultdeps
    PERL_CR_SMOKER_CURRENT = Contenticious-0.391
    PERL_CR_SMOKER_RUNONCE = 1
    PERL_EXTUTILS_AUTOINSTALL = --defaultdeps
    PERL_MM_USE_DEFAULT = 1
    PERL_USE_UNSAFE_INC = 0
    SHELL = /bin/bash
    TERM = putty-256color

Perl special variables (and OS-specific diagnostics, for MSWin32):

    $^X = /home/cpan4/install/bin/perl
    $UID/$EUID = 1005 / 1005
    $GID = 1005 1005
    $EGID = 1005 1005

Perl module toolchain versions installed:

    Module              Have      
    ------------------- ----------
    CPAN                2.16      
    CPAN::Meta          2.150010  
    Cwd                 3.67      
    ExtUtils::CBuilder  0.280225  
    ExtUtils::Command   7.25_01   
    ExtUtils::Install   2.04      
    ExtUtils::MakeMaker 7.25_01   
    ExtUtils::Manifest  1.70      
    ExtUtils::ParseXS   3.34      
    File::Spec          3.67      
    JSON                2.90      
    JSON::PP            2.27400_02
    Module::Build       0.4222    
    Module::Signature   n/a       
    Parse::CPAN::Meta   2.150010  
    Test::Harness       3.38      
    Test::More          1.302073  
    YAML                1.23      
    YAML::Syck          1.29      
    version             0.9917    


--

Summary of my perl5 (revision 5 version 26 subversion 0) configuration:
  Commit id: 1b92e6949b737e92f61827f9c92afce9218e30ba
  Platform:
    osname=linux
    osvers=3.16.0-4-amd64
    archname=x86_64-linux-thread-multi-ld
    uname='linux digitalis 3.16.0-4-amd64 #1 smp debian 3.16.36-1+deb8u2 (2016-10-19) x86_64 gnulinux '
    config_args='-Dusedevel -DDEBUGGING -Dusethreads -Duselongdouble -Duse64bitall -Doptimize=-O3 -Dprefix=/home/cpan4/install -Uversiononly -Uman1dir -Uman3dir -des'
    hint=recommended
    useposix=true
    d_sigaction=define
    useithreads=define
    usemultiplicity=define
    use64bitint=define
    use64bitall=define
    uselongdouble=define
    usemymalloc=n
    default_inc_excludes_dot=define
    bincompat5005=undef
  Compiler:
    cc='cc'
    ccflags ='-D_REENTRANT -D_GNU_SOURCE -fwrapv -DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2'
    optimize='-O3 -g'
    cppflags='-D_REENTRANT -D_GNU_SOURCE -fwrapv -DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include'
    ccversion=''
    gccversion='4.9.2'
    gccosandvers=''
    intsize=4
    longsize=8
    ptrsize=8
    doublesize=8
    byteorder=12345678
    doublekind=3
    d_longlong=define
    longlongsize=8
    d_longdbl=define
    longdblsize=16
    longdblkind=3
    ivtype='long'
    ivsize=8
    nvtype='long double'
    nvsize=16
    Off_t='off_t'
    lseeksize=8
    alignbytes=16
    prototype=define
  Linker and Libraries:
    ld='cc'
    ldflags =' -fstack-protector-strong -L/usr/local/lib'
    libpth=/usr/local/lib /usr/lib/gcc/x86_64-linux-gnu/4.9/include-fixed /usr/include/x86_64-linux-gnu /usr/lib /lib/x86_64-linux-gnu /lib/../lib /usr/lib/x86_64-linux-gnu /usr/lib/../lib /lib /lib64 /usr/lib64
    libs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
    perllibs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
    libc=libc-2.19.so
    so=so
    useshrplib=false
    libperl=libperl.a
    gnulibc_version='2.19'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs
    dlext=so
    d_dlsymun=undef
    ccdlflags='-Wl,-E'
    cccdlflags='-fPIC'
    lddlflags='-shared -O3 -g -L/usr/local/lib -fstack-protector-strong'


Characteristics of this binary (from libperl): 
  Compile-time options:
    DEBUGGING
    HAS_TIMES
    MULTIPLICITY
    PERLIO_LAYERS
    PERL_COPY_ON_WRITE
    PERL_DONT_CREATE_GVSV
    PERL_IMPLICIT_CONTEXT
    PERL_MALLOC_WRAP
    PERL_OP_PARENT
    PERL_PRESERVE_IVUV
    PERL_TRACK_MEMPOOL
    PERL_USE_DEVEL
    USE_64_BIT_ALL
    USE_64_BIT_INT
    USE_ITHREADS
    USE_LARGE_FILES
    USE_LOCALE
    USE_LOCALE_COLLATE
    USE_LOCALE_CTYPE
    USE_LOCALE_NUMERIC
    USE_LOCALE_TIME
    USE_LONG_DOUBLE
    USE_PERLIO
    USE_PERL_ATOF
    USE_REENTRANT_API
  Built under linux
  Compiled at Mar 31 2017 23:44:13
  %ENV:
    PERL="/home/cpan4/install/bin/perl"
    PERL5LIB=""
    PERL5OPT=""
    PERL5_CPANPLUS_IS_RUNNING="16984"
    PERL5_CPAN_IS_EXECUTING="/home/cpan4/.cpan/build/Text-Markdown-1.000031-0/Makefile.PL"
    PERL5_CPAN_IS_RUNNING="16984"
    PERL5_CPAN_IS_RUNNING_IN_RECURSION="18389,16984"
    PERL_AUTOINSTALL="--defaultdeps"
    PERL_CR_SMOKER_CURRENT="Contenticious-0.391"
    PERL_CR_SMOKER_RUNONCE="1"
    PERL_EXTUTILS_AUTOINSTALL="--defaultdeps"
    PERL_MM_USE_DEFAULT="1"
    PERL_USE_UNSAFE_INC="0"
  @INC:
    /home/cpan4/install/lib/perl5/site_perl/5.26.0/x86_64-linux-thread-multi-ld
    /home/cpan4/install/lib/perl5/site_perl/5.26.0
    /home/cpan4/install/lib/perl5/5.26.0/x86_64-linux-thread-multi-ld
    /home/cpan4/install/lib/perl5/5.26.0