Repository: spack/spack

Issue:
Installation issue: netcdf-c older versions no longer hosted on mirror site
### Spack version
0.14.1

### Steps to reproduce the issue

```console
$ spack install netcdf-c@4.6.2
==> 35562: Installing netcdf-c
==> Fetching https://www.gfd-dennou.org/arch/netcdf/unidata-mirror/netcdf-c-4.6.2.tar.gz

curl: (22) The requested URL returned error: 404 Not Found
==> Failed to fetch file from URL: https://www.gfd-dennou.org/arch/netcdf/unidata-mirror/netcdf-c-4.6.2.tar.gz
    URL https://www.gfd-dennou.org/arch/netcdf/unidata-mirror/netcdf-c-4.6.2.tar.gz was not found!
==> Fetching from https://www.gfd-dennou.org/arch/netcdf/unidata-mirror/netcdf-c-4.6.2.tar.gz failed.
==> Error: FetchError: All fetchers failed for spack-stage-netcdf-c-4.6.2-k35zgwrkyyiqm76qbly72fh3u3gxov6c
```
### Additional information
The issue is stemming from the mirror site https://www.gfd-dennou.org/arch/netcdf/unidata-mirror no longer hosting some of the older packages of netcdf. These packages are still hosted on netcdf's github page. I'm really opening this issue to suggest a change of the primary download url for netcdf-c to the official github releases page for the project. 


Discussion:
This will be fixed by #15641
Closing, since this has been solved by NetCDF maintainers and the mirror site is up again:
```console
$ spack fetch netcdf-c@4.6.2
[...]
==> Fetching from file:///home/culpo/spack-resources/mirrors/sources/_source-cache/archive/c3/c37525981167b3cd82d32e1afa3022afb94e59287db5f116c57f5ed4d9c6a638.tar.gz failed.
==> Fetching https://www.gfd-dennou.org/arch/netcdf/unidata-mirror/netcdf-c-4.6.2.tar.gz
######################################################################## 100,0%
```
See discussion in #15641 

Resolving patch:
diff --git a/var/spack/repos/builtin/packages/netcdf-c/package.py b/var/spack/repos/builtin/packages/netcdf-c/package.py
--- a/var/spack/repos/builtin/packages/netcdf-c/package.py
+++ b/var/spack/repos/builtin/packages/netcdf-c/package.py
@@ -13,16 +13,18 @@ class NetcdfC(AutotoolsPackage):
 
     homepage = "http://www.unidata.ucar.edu/software/netcdf"
     git      = "https://github.com/Unidata/netcdf-c.git"
-    url      = "https://www.gfd-dennou.org/arch/netcdf/unidata-mirror/netcdf-c-4.7.2.tar.gz"
+    url      = "ftp://ftp.unidata.ucar.edu/pub/netcdf/netcdf-c-4.7.3.tar.gz"
 
     def url_for_version(self, version):
         if version >= Version('4.6.2'):
-            url = "https://www.gfd-dennou.org/arch/netcdf/unidata-mirror/netcdf-c-{0}.tar.gz"
+            url = "ftp://ftp.unidata.ucar.edu/pub/netcdf/netcdf-c-{0}.tar.gz"
         else:
-            url = "https://www.gfd-dennou.org/arch/netcdf/unidata-mirror/netcdf-{0}.tar.gz"
+            url = "ftp://ftp.unidata.ucar.edu/pub/netcdf/netcdf-{0}.tar.gz"
 
         return url.format(version.dotted)
 
+    maintainers = ['skosukhin', 'WardF']
+
     version('master', branch='master')
     version('4.7.3',   sha256='8e8c9f4ee15531debcf83788594744bd6553b8489c06a43485a15c93b4e0448b')
     version('4.7.2',   sha256='b751cc1f314ac8357df2e0a1bacf35a624df26fe90981d3ad3fa85a5bbd8989a')
diff --git a/var/spack/repos/builtin/packages/netcdf-cxx4/package.py b/var/spack/repos/builtin/packages/netcdf-cxx4/package.py
--- a/var/spack/repos/builtin/packages/netcdf-cxx4/package.py
+++ b/var/spack/repos/builtin/packages/netcdf-cxx4/package.py
@@ -12,10 +12,12 @@ class NetcdfCxx4(AutotoolsPackage):
     sharing of array-oriented scientific data. This is the C++ distribution."""
 
     homepage = "https://www.unidata.ucar.edu/software/netcdf"
-    url      = "https://www.unidata.ucar.edu/downloads/netcdf/ftp/netcdf-cxx4-4.3.1.tar.gz"
+    url      = "ftp://ftp.unidata.ucar.edu/pub/netcdf/netcdf-cxx4-4.3.1.tar.gz"
+
+    maintainers = ['WardF']
 
     version('4.3.1', sha256='6a1189a181eed043b5859e15d5c080c30d0e107406fbb212c8fb9814e90f3445')
-    version('4.3.0', sha256='f4766d5a19c91093be80ddd2eaf1fbbd8d203854cc69fc73d2ad293b099ac799')
+    version('4.3.0', sha256='e34fbc6aba243ec82c23e9ee99db2430555ada849c54c1f3ab081b0ddd0f5f30')
 
     # Usually the configure automatically inserts the pic flags, but we can
     # force its usage with this variant.
diff --git a/var/spack/repos/builtin/packages/netcdf-fortran/package.py b/var/spack/repos/builtin/packages/netcdf-fortran/package.py
--- a/var/spack/repos/builtin/packages/netcdf-fortran/package.py
+++ b/var/spack/repos/builtin/packages/netcdf-fortran/package.py
@@ -13,9 +13,9 @@ class NetcdfFortran(AutotoolsPackage):
     distribution."""
 
     homepage = "https://www.unidata.ucar.edu/software/netcdf"
-    url      = "https://www.gfd-dennou.org/arch/netcdf/unidata-mirror/netcdf-fortran-4.5.2.tar.gz"
+    url      = "ftp://ftp.unidata.ucar.edu/pub/netcdf/netcdf-fortran-4.5.2.tar.gz"
 
-    maintainers = ['skosukhin']
+    maintainers = ['skosukhin', 'WardF']
 
     version('4.5.2', sha256='b959937d7d9045184e9d2040a915d94a7f4d0185f4a9dceb8f08c94b0c3304aa')
     version('4.4.5', sha256='2467536ce29daea348c736476aa8e684c075d2f6cab12f3361885cb6905717b8')


Test patch: