
Dockerfile to reproduce:
```dockerfile
FROM debian:buster-slim as build

# Install dependencies
RUN apt-get update && apt-get install -y \
    build-essential \
    autoconf \
    automake \
    libtool \
    flex \
    bison \
    gperf \
    gawk \
    m4 \
    make \
    openssl \
    libssl-dev \
    libreadline-dev \
    && rm -rf /var/lib/apt/lists/*

# Check versions
# RUN autoconf --version
# RUN automake --version
# RUN libtoolize --version
# RUN flex --version
# RUN bison --version
# RUN gperf --version
# RUN gawk --version
# RUN m4 --version
# RUN make --version
# RUN openssl version

# Download virtuoso
RUN mkdir /build
WORKDIR /build
ADD https://github.com/openlink/virtuoso-opensource/releases/download/v7.2.11/virtuoso-opensource-7.2.11.tar.gz virtuoso-opensource-7.2.11.tar.gz
RUN tar -xzf virtuoso-opensource-7.2.11.tar.gz
WORKDIR /build/virtuoso-opensource-7.2.11

# Build
ENV LC_ALL=C.UTF-8
RUN ./autogen.sh
#ENV CFLAGS="-O2 -m64"
RUN ./configure
RUN make -j 4
```


```bash
docker build . -t virtuoso --progress=plain
```

Error output:
```
171.0 grep: input file 'mkvad.output' is also the output
171.0 make[2]: *** [Makefile:659: isparql_dav.vad] Error 1
171.0 make[1]: *** [Makefile:492: all-recursive] Error 1
171.0 make: *** [Makefile:691: all-recursive] Error 1
```
Virtuoso v7.2.11 doesn't compile on Debian Buster
This is a GitHub Issue
repo:virtuoso-opensource
owner:openlink
Title : Virtuoso v7.2.11 doesn't compile on Debian Buster
Issue date:

--- start body ---

Dockerfile to reproduce:
```dockerfile
FROM debian:buster-slim as build

# Install dependencies
RUN apt-get update && apt-get install -y \
    build-essential \
    autoconf \
    automake \
    libtool \
    flex \
    bison \
    gperf \
    gawk \
    m4 \
    make \
    openssl \
    libssl-dev \
    libreadline-dev \
    && rm -rf /var/lib/apt/lists/*

# Check versions
# RUN autoconf --version
# RUN automake --version
# RUN libtoolize --version
# RUN flex --version
# RUN bison --version
# RUN gperf --version
# RUN gawk --version
# RUN m4 --version
# RUN make --version
# RUN openssl version

# Download virtuoso
RUN mkdir /build
WORKDIR /build
ADD https://github.com/openlink/virtuoso-opensource/releases/download/v7.2.11/virtuoso-opensource-7.2.11.tar.gz virtuoso-opensource-7.2.11.tar.gz
RUN tar -xzf virtuoso-opensource-7.2.11.tar.gz
WORKDIR /build/virtuoso-opensource-7.2.11

# Build
ENV LC_ALL=C.UTF-8
RUN ./autogen.sh
#ENV CFLAGS="-O2 -m64"
RUN ./configure
RUN make -j 4
```


```bash
docker build . -t virtuoso --progress=plain
```

Error output:
```
171.0 grep: input file 'mkvad.output' is also the output
171.0 make[2]: *** [Makefile:659: isparql_dav.vad] Error 1
171.0 make[1]: *** [Makefile:492: all-recursive] Error 1
171.0 make: *** [Makefile:691: all-recursive] Error 1
```
--- end body ---
